Laboratory animals

1. Makarova M.N., Rybakov A.V. , Gushchin J.A., Shedko V.V., Muzhikyan A.A., Makarov V.G. Anatomical and physiological characteristics of the digestive tract in humans and laboratory animals // International Bulletin of Veterinary Medicine. – 2016, № 1. – C. 82-104.

2. Voronin SE, MN Makarova, Kryshen KL, Alyakrinskaya AA, AV Rybakov Ferrets, like laboratory animals // International Bulletin of Veterinary Medicine. – 2016, № 2. – C. 103-116.

3. Rybakova A.V., Kovaleva M.A., Kalatanova A.V., Vanatiev G.V., Makarova M.N. Mini-pigs as an object of preclinical studies // International Bulletin of Veterinary Medicine. – 2016, № 3. – C. 168-176.

4. Voronin S.E., Makarova M.N., Kryshen K.L., Alyakrinskaya A.A., Rybakova A.V. Ferrets as laboratory animals // Proceedings of the IV-th International Congress of Veterinary Pharmacology and Toxicology “Effective and safe drugs in veterinary medicine.” St. Petersburg, 2016. – C. 46-47.

5. Goryacheva M.A., Gushchin J.A., Kovaleva M.A., Makarova M.N. The possibility of using lidocaine hydrochloride and potassium chloride for the euthanasia of laboratory rabbits // Proceedings of the IV-th International Congress of Veterinary Pharmacology and Toxicology “Effective and safe drugs in veterinary medicine.” St. Petersburg, 2016. – C. 55-56.

6. Rybakova AV, Makarova MN Proper maintenance and care of the dwarf pigs for preclinical issdovany // Proceedings of the IV-th International Congress of Veterinary Pharmacology and Toxicology “Effective and safe drugs in veterinary medicine.” St. Petersburg, 2016. C. 46-47.

7. Kalatanova A.V., Avdeeva O.I., Makarova M.N., Muzhikyan A.A., Shedko V.V., Vanatiev G.V., Makarov V.G., Carlina M.V., Pozharitskaya O.N. Using the hamster cheek pouches during preclinical studies of drugs, oral dispersible // Pharmacia. – 2016, №7. – P. 50-55.

8. Rybakova A.V., Makarova M.N., Makarov V.G. Use of rabbits in pre-clinical studies // International bulletin of veterinary Medicine. -2016, No. 4.-C. 102-106.

9. Gayday E.A., Makarova M.N. The use of degu as laboratory animals // International bulletin of veterinary Medicine. -2017, No. 1.-C. 57-66.

10. Rybakova A.V., Makarova M.N. Zootechnical characteristics of the content of dwarf pigs in experimental vivariums // International bulletin of veterinary Medicine. -2017, No. 1.-C. 66-74.

11. Makarova M.N., Makarov V.G., Rybakova A.V., Zozulya O.K. Feeding laboratory animals. Basic rations. Message 1 // International bulletin of veterinary Medicine. -2017, No. 2.-C. 91-105.

12. Makarova M.N., Makarov V.G., Shekunova E.V. Selection of the species of animals for assessing the neurotoxicity of pharmacological substances // International bulletin of veterinary Medicine. – 2017, No. 2. – C. 106-113.

13. Rybakova A.V., Makarova M.N. The use of gerbils for biomedical research // International bulletin of veterinary Medicine. -2017, No. 2.-C. 117-124.

14. Бондарева Е.Д., Рыбакова А.В., Макарова М.Н. Зоотехнические характеристики содержания морских свинок в экспериментальных вивариях // Международный вестник ветеринарии. – 2017, № 3. – С. 108-115. Зоотехнические характеристики содержания морских свинок в экспериментальных вивариях

15. Гущин Я.А., Мужикян А.А., Шедько В.В., Макарова М.Н., Макаров В.Г. Сравнительная анатомия верхнего отдела желудочно-кишечного тракта экспериментальных животных и человека // Международный вестник ветеринарии. – 2017, № 3.– С. 116-129. Сравнительная анатомия верхнего отдела желудочно-кишечного тракта экспериментальных животных и человека 

16. Макарова М.Н., Макаров В.Г. Питание лабораторных животных. Признаки дефицита и избытка белка, жира, углеводов и витаминов. Сообщение 2. // Международный вестник ветеринарии. – 2017,  № 3. – С. 129-138. Питание лабораторных животных. Признаки дефицита и избытка белка, жира, углеводов и витаминов. Сообщение 2.

17. Макарова М.Н., Рыбакова А.В., Кильдибеков К.Ю. Требования к освещенности в помещениях вивария и питомника лабораторных животных // Международный вестник ветеринарии. – 2017, № 3. – С. 138-147. Требования к освещенности в помещениях вивария и питомника лабораторных животных

18. Рыбакова А.В., Макарова М.Н. Использование хомяков в биомедицинских исследованиях // Международный вестник ветеринарии. – 2017, № 3. – С. 148-157. Использование хомяков в биомедицинских исследованиях  

19. Rudenko L., Kiseleva I., Krutikova E., Stepanova E., Rekstin A., Donina S., Pisareva M., Grigorieva E., Kryshen K., Muzhikyan A., Makarova M., Sparrow E.G., Marie-Paule G.T. Rationale for vaccination with trivalent or quadrivalent live attenuated influenza vaccines: Protective vaccine efficacy in the ferret model // PLOS ONE. – 2018. – P. 1-19.

20. Rybakova AV, Makarova MN, Kukharenko AE, Vichare AS, Rueffer F-R. Current requirements for and approaches to dosing in animal studies. Vedomosti Nauchnogo tsentra ekspertizy sredstv meditsinskogo primeneniya // Тhе Bulletin of the Scientific Centre for Expert Evaluation of Medicinal Products. – 2018, 8(4). – Р. 207-217. https://doi.org/10.30895/1991-2919-2018-8-4-207-217.  Abstract.Today, within the context of harmonisation of requirements in the international pharmaceutical market, there is a trend towards development of common standards, including in the field of preclinical studies. The reliability and reproducibility of experimental data obtained in various laboratories using animals cannot be guaranteed unless the 3Rs principles are observed (the principles of humane experimental technique) to ensure the welfare of animals. The present paper analyses Russian and foreign recommendations on different administration routes and administered volumes as applied to mice, rats, guinea pigs, and rabbits — the most frequently used laboratory animals. The paper systematises literature data on oral/intragastric, subcutaneous, intramuscular, intravenous and intraperitoneal routes of administration. It assesses potential complications of each route of administration, and negative effects on both health and well-being of laboratory animals, as well as on the results of experiments. The paper also touches upon some anatomical and physiological characteristics of laboratory animals, potential opportunities for feed and water deprivation, ways of reducing pain in animals. The results of comparison of administered volumes helped to determine optimal recommended and maximum administered volumes [Full text is available in Russian].

21. Kryshen K.L., Katelnikova А.Е., Makarova M.N., Makarov V.G. Peculiarities of Biomedical Experiments Involving Ferrets. Laboratory Animals for Science. – 2019, 2. https://doi.org/10.29296/2618723X-2019-02-10 Abstract. Today ferrets are becoming increasingly popular in biomedical studies. Ferrets possess unique zootechnical characteristics, have a high susceptibility to virulent strains of the influenza virus and are most widely used in experimental studies to evaluate the immunogenic and protective properties of anti-influenza vaccines and the effectiveness of antiviral drugs. Influenza virus in ferrets causes infections that occur with clinical symptoms similar to those of a human infection (fever, runny nose, lethargy, weight loss, etc.). In addition, ferrets belong to predators, that may increase their value for preclinical studies as an animal species alternative to rodents. However, ferrets require special conditions and veterinary care. The purpose of this paper was to systematize the literature data and our own experience of working with ferrets in the laboratory. In an experimental vivarium, ferrets usually contain in cages with a height of at least 50 cm and a floor area depending on body weight from 1,500 to 6,000 cm2 per animal. Elements of the environment enrichment must be present in the cage such as hammocks, stairs, tunnels, balls. Environment temperature and humidity parameters for ferrets do not significantly differ from that for rodents. For ferrets that are used only in the experiment, a normal lighting cycle of 12 hours a day/12 hours a night is sufficient. Because ferrets are strict predators, they need a diet rich in protein and fat, but low in fiber. In the experiment most often used young adult male ferrets aged from 5 to 12 months, from 3 to 5 animals per group. Special attention in experimental work with ferrets should be given to anesthesia. Thus, the use of gas anesthesia, as a rule, is unacceptable, since repeated anesthesia during the experiment leads to marked changes in the lungs. One of the main parameters for assessing the development of influenza infection in ferrets is body temperature. The article proposes a method for measuring temperature with special implantable sensors, which allows to accurately and correctly analyse the dynamics of this parameter throughout the experiment [Full text is available in Russian].

22. Makarova M., Shubin D., Makarov V.G. The respiratory rate in preclinical studies. Laboratory Animals for Science. – 2019, 3. https://doi.org/10.29296/2618723X-2019-03-03 Abstract. Study of the respiratory function in laboratory animals is a frequent task in the study of drug toxicity, to assess pharmacological safety, the study of pharmacodynamics. The associated question of normal values of respiratory motion frequency (respiratory rate, RR) in healthy animals. The purpose of this study was to assess the respiratory rate in the most frequently used in preclinical studies of laboratory animal species: mouse (n=10♀, n=10♂), rat (n=20♀, n=20♂), guinea pig (n=20♀, n=20♂), rabbit (n=20♀, n=20♂) and their comparison with the literature data. All animals were first measured without general anesthesia, then the same animals were anesthetized and their measurements were repeated. Also, the effect of accustoming rabbits to the measurement procedure (over a period of 2 weeks) in the additional group (n=5♀, n=5♂) was assessed, and the respiratory rate in young rabbits was assessed, also in the additional group of animals (n=5♀, n=5♂). RR indicators in mice coincided with the literature and made 200-283 respiratory movements per minute. At the same time, the data obtained on non-anesthetized animals turned out to be statistically higher. Respiratory rate indicators in rats with and without general anesthesia coincided with the literature and amounted to 91-106 breathing movements per minute. Female RR was statistically significantly lower in females than in males when using anesthesia. In guinea-pigs, the values of RR fully coincided with the literature data and amounted to 89-120 respiratory movements per minute, while the use of anesthesia in both males and females of RR was reduced. Among the studied animal species, this species was most suitable for taking readings of RR without using anesthesia. When analyzing the data obtained on rabbits, we drew attention to the extremely low value of RR in rabbits at rest, in the reference veterinary literature and a number of experimental works 30-80 breathing movements per minute. In other experimental works this indicator in intact females of rabbits was 120-200 movements per minute. We managed to register relatively low values of RR only in male rabbits in general anesthesia (79±9). In male rabbits without anesthesia, this indicator was 302±19 respiratory movements per minute, in females without anesthesia it was found that RR was 441±13, and in general anesthesia RR was reduced to 233±29 respiratory movements per minute. We assumed that the rabbits, before the manipulation, need to be accustomed to the measurement procedure, and within 2 weeks they were accustomed to it. Also, the RR was measured in young rabbits. It was shown that the adaptation of animals to the measurement procedure has a response to the reduction of RR in males of rabbits in consciousness to 224±17, in females to 163±9. The use of younger animals at the age of 8-9 months in the registration of RR also had its effect on the RR index, it was 157±23 and 114±11 in males and females, respectively, and was lower than in older animals (12-14 weeks). The research gave opportunity us to formulate some practical recommendations for measuring RR in laboratory animals [Full text is available in Russian].

23. Kargopolceva D.R., Kryshen K.L., Makarova M.N., Katelnikova A.E., Zueva A.A., Matichin A.А., Gajdaj D.S.Impact assessment of potential risks from warmer enviromental temperature of laboratory animals (mice, rats, guinea pigs) outside the recommendated range for main biological parameters // Laboratory Animals for Science. – 2019, №3. https://doi.org/10.29296/2618723X-2019-03-09 Abstract. Adverse environmental conditions can lead to animal stress. That, in turn, might trigger inaccurate study results. Creature of enabling environment therefore is essential to perform every preclinical study. The maintain a comfortable environmental temperature occupies an important place in housing laboratory animals. Today guidelines and recommendations for maintenance and care for laboratory animals have already produced and it contains differ data about average comfortable temperature of animal housing, like mice, rats and guinea pigs. Although it is impossible to exclude the occurrence of emergency situations in sources, in which the microclimate indicators, in particular the temperature of laboratory animals, deviate from the recommended ranges. Animals have a preferred temperature range that is comfortable and relatively warm, called the thermoneutral zone. There are very few literary data which describe the influence of small increasing of environmental temperature on tested parameters. In our researching work we described the effect of warmer environmental temperature on main biological parameters of male and female mice, rats and guinea pigs like: general animal state, body weight, hematological and blood biochemical parameters and weight of internal organs to body weight ratio. Experimental animals were housed at the temperature: 27, 28, 29°C and 30°C for week. Other animals were housed for 4 weeks at the initial temperature 27°C with gradual increasing by 1°C weekly until 30°C. The study found that the small increasing of environmental temperature (between 27 and 30°C) didn’t effect on animal vital signs and risks in case of emergency situations related to the provision of the recommended content temperature are minimal [Full text is available in Russian].

24. Katelnikova A.E., Zueva A.A., Matichin A.A., Kargopolceva D.R., Gajdaj D.S. Approbation of the cisplatin-induced acute vomiting model in ferret and choice of reference treatment // Laboratory Animals for Science. – 2019, 3. https://doi.org/10.29296/2618723X-2019-03-10 Abstract. The absent of effective in all clinical and other conditions nausea and vomiting antiemetic treatment demonstrate the need for research in this area. This raises the question, what models are most suitable for such studies. In the early 1980’s it was seen ferrets suffered from acute vomiting induced by high dose of cisplatin. It was suggested using ferrets as an alternative test-system instead dogs, cats and monkeys which exploited previously in researches of vomiting induced by cytotoxics and testing of potential antiemetic medicines. Cisplatin-induced vomiting in ferret has used more than 30 years. It allowed stablishing and implementing antiemetic medicines such as ondansetron, granisetron, aprepit, fosaprepitant in clinical usage. The aim of this study was approbation of cisplatin-induced acute vomiting in ferret with formulation of choice reference medicines. Ferrets were separated into 3 groups of 4 animals. Three groups were administrated intraperitoneally cisplatin in 10 mg/kg. Ondasetron was administrated intramuscularly to animals in dose 1 mg/kg. Emend V/V was administrated intravenous to animals in dose 3 mg/kg. Follow indicators were chosen: latent period, number of retching or vomiting, which was registered on typical signs during 4 hours since the cisplatin administration. Our study demonstrates that the average latent period was 2 hours and summary number of retching or vomiting was 41 ± 17 (M±SD) in control group. Ondasetron and Emend V/V showed pronounced antiemetic effect expressed by significantly decrease retching and it wasn’t registered developing vomiting in ferrets. The administration of referent medicines didn’t effect on duration latent period. When data were interpreted there were taken into account factors affecting the reproducing of the model like administration route of pathological inductor, using of anesthesia, animal number in each group and the source where the animals were grown as the most non-obvious factor [Full text is available in Russian].

25. Kargopoltceva D.R., Makarova M.N., Zueva A.A., Kildibekov K.Yu. Impact Assessment оf Potential Risks From Enviromental Temperature Decrising оf Laboratory Animals (Mice, Rats, Guinea Pigs) Outside the Recommended Range for Main Biological Parameters // Laboratory Animals for Science. – 2019, 4. https://doi.org/10.29296/2618723X-2019-04-02 Abstract. Risks are the possibility of an adverse situation attracts various losses. There are risks in all spheres of activity including the work of vivariums and sources. It is important to observe the necessary environmental conditionals (room temperature, air humidity and air exchange) and light cycle. It may be deviations from the established standards for these microclimate indicators that, in turn, might severely effects on animal health and trigger inaccurate study results in case emergency situations in the vivarium. In previous work study was conduct to assess the potential risks resulting from elevation of environmental temperature of laboratory animals (mice, rats and guinea pigs). It was found, that an environmental temperature increase by 4°C above the upper limit of the recommended ranges didn’t effect on vital indicators of laboratory animals. In current study we researched risks emerging by decrease of the environmental temperature 3°C above lower recommended range influence main health indicators like: general animal state, body weight, hematological and blood biochemical parameters and weight of internal organs to body weight ratio. Mice, rats and guinea pigs were housed at the temperature: 19, 18 and 17°C for week. Other animals were housed for 3 weeks at the initial temperature 19°C with gradual lowering by 1°C weekly until 17°C. The study found that the small lowering of environmental temperature (between 19 and 17°C) didn’t effect on animal vital signs and risks in case of emergency situations related to the provision of the recommended content temperature are minimal [Full text is available in Russian].

26. Gajdaj Е.А., Gajdaj D.S. Genetic variety of laboratory mice and rats: history of occurrence, methods of obtaining and control. Laboratory Animals for Science. – 2019, 4. https://doi.org/10.29296/2618723X-2019-04-09 Abstract. The review is devoted to the diversity of laboratory rats and mice strains used in biomedical research. Laboratory animals are indispensable assistants to scientists to solve the main tasks of modern biomedicine – the prevention and treatment of various diseases. The most popular objects for research are rodents: mice and rats. Experimental biology that appeared in the 17th century required the use of animal models. The first mention of the use of mice and rats for scientific purposes dates back to this time. Due to the relative cheapness of the content, fertility and rapid reproduction of rats and mice they have gained high popularity as model organisms. Development of science lead to necessary to increase the accuracy and reproducibility of experiments by reducing the influence of genetic differences between individuals, i.e. in breeding linear rats. Today in the world there are about a thousand lines of rats and more than ten thousand lines of mice, including not only outbred and inbred, but also transgenic and knockout lines. Breeding of laboratory animals’ lines made it possible to conduct several previously inaccessible studies. The most common biomedical studies use the widespread lines of Wistar and SD rats and Balb/C and CD-1 mice. The choice of line should be carried out by scientists for specific research purposes and taking into account the genetic characteristics of the animals used. It is imperative to keep the pure of lines to produce reproducible results from research to research. To keep the pure of line it is sufficient to regularly monitor animals and strictly follow the breeding procedure. An important method for ensuring the quality of laboratory animals is genetic control. If in the experiment there was an accidental crossbreeding with animals of a different genotype, it is almost impossible to restore the line’s homozygosity preserving the original genotype. Those animals are subject to annihilation [Full text is available in Russian].

27. Makarova M.N., Ilyinskaya М.А. Facilities of the Breeding Performance of BALB/с mice // Laboratory Animals for Science. – 2020, № 1. https://doi.org/10.29296/2618723X-2020-01-04 Abstract. BALB/c mice are widely used in all areas of biomedical research. This is one of the oldest lines, which is considered noncancerous, despite the available data on the frequency of spontaneous neoplastic formations of the mammary glands, lungs and kidneys, which in some sublines can reach 40%. Many cell and tissue cultures that are widely used in biomedical experiments originate from BALB/c mice. Breeding success among rodents kept in laboratory conditions consists of a combination of factors related to the health of the livestock, as well as the conditions of maintenance (population density, feeding, environmental parameters). The review considers and systematizes the influence of certain factors on the reproduction of BALB/c mice. Temperature affects mice mainly when they are kept at elevated values. The humidity of the environment significantly affects the health of mice. The data related to both a decrease and an increase in humidity are considered. Indicators of ventilation and air exchange also have a significant impact on the reproduction of the mice population. The most important indicator that affects the welfare of animals is considered to be the concentration of ammonia. The intensity and duration of lighting affect behavior, physiology, and reproductive parameters of BALB/c mice. The greatest danger is high intensity of lighting and changes in circadian cycles, which can cause phototoxic retinopathy and have a systemic effect, reducing reproductive function. It is impossible to exclude the influence of nutrition factors on reproductive function. It is shown that both the deficiency of nutrients and their redundancy have a negative effect on reproduction indicators. Enrichment of the habitat with various elements, including nesting material, has a positive effect on the fertility of BALB/c mice, while the type of enrichment and nesting material does not play a significant role. The review concludes with recommendations from the Jackson Laboratory specialists for optimizing the reproduction of BALB/c mice [Full text is available in Russian].

28. Voitenko N.G, Makarova M.N., Zueva A.A. Variability of blood biochemical parameters and establishing of reference ranges in nonclinical studies. Part 1: rats // Laboratory Animals for Science. – 2020, № 1. https://doi.org/10.29296/2618723X-2020-01-06 Abstract. Establishing of current reference ranges for laboratory animal parameters is topical problem both in clinical and nonclinical studies. Retrospective analysis of 11 serum biochemical parameters in rats was conducted. Blood samples were collected from 195 male and 184 female rats (age 12–20 weeks and body weight 250–350 g.). It was found that outliers of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were identified most frequent than other blood biochemical parameters in rats. This fact requiring increase in the number of repeatability in analyzing of blood parameters has to be taken into account when planning of study. Reference ranges of data base including creatinine, urea, AST, ALT, alkaline phosphatase, cholesterol, triglycerides, total protein, albumin, glucose and total bilirubin and its’ inter-individual variance were identified. It was determined that alkaline phosphatase, triglycerides, glucose and total bilirubin have greatest inert-individual variance (more than 30%). The data have been received from retrospective analysis was compared with reference interval of rat biochemical parameters from three large sources (Charles River, Taconic and Envigo). Reference intervals from literature sources also indicate high variance of some enzyme activity (including alkaline phosphatase), glucose, total bilirubin and triglycerides. Our calculated reference intervals was comparable with the same data from literature sources. The results indicate that retrospective data analyzing allowing to access more accurate reference interval from larger data base without compromising ethical principles is preferable to use. Comparative analysis of inter-individual variance of rat and human blood biochemical parameters show the presence of species differences which need should be considered in discussion the preclinical study results [Full text is available in Russian].

29. Kovaleva М.А. Review of The Ellegaard Göttingen Minipigs А/S news letter // Laboratory Animals for Science. – 2020, № 1  http://labanimalsjournal.ru/en/2618723x-2020-01-09  [Full text is available in Russian].

 30. Bondareva E.D. Proper waste management. Vivarium biological waste // Laboratory Animals for Science. – 2020, №1. https://doi.org/10.29296/2618723X-2020-01-01 Abstract. The article shows the differences in the interpretation of the concepts of biological and medical waste by different regulatory documents. Possible options for the management of biological waste from experimental vivariums within the framework of regulatory acts in the field of ensuring sanitary and epidemiological well-being are considered. An important stage of the waste management algorithm is the sorting stage, which determines the future fate of the waste and can affect the safety of people and the environment. The heterogeneous composition of biological wastes from experimental vivariums does not allow a clear distinction to be made between biological and medical wastes. For medical waste, there is SanPiN 2.1.7.2790-10 “Sanitary and epidemiological requirements for the treatment of medical waste”, for biological waste Veterinary and sanitary rules for the collection, disposal and destruction of biological waste No. 13-7-2 / 469. The legislation of the Russian Federation does not clearly define the belonging of all waste from experimental vivariums to any waste group. Due to the complexity of differentiating biological and medical wastes, mistakes can be made not only at the sorting stage, but also at the stages of disinfection, temporary storage, transportation and disposal. Different waste groups require different approaches to handling them. Thus, the waste management process is a time-consuming stage-by-stage process that requires the correct implementation of regulatory requirements. Mistakes at different stages can become a threat to human health and the environment [Full text is available in Russian].

31. Voitenko N.G., Makarova M.N., Kovaleva M.A. Variability of blood biochemical parameters and establishment of reference intervals in preclinical studies. Part 2: rabbit. Laboratory Animals for Science. – 2020, №2. https://doi.org/10.29296/2618723X-2020-02-01 Abstract. The data of the biochemical analysis are the reference for most of the preclinical studies. The establishment and revision of reference ranges of biochemical indicators for all types of used laboratory animals is an important task for each testing center. In the Russian Federation, rabbits are widely used for various studies, for example, the study of the general toxic properties of original drugs, or long-acting drugs, the study of the specific activity of drugs used for the treatment of the visual organs and the musculoskeletal system, etc. Despite the sufficient study of the species as a whole, Russian periodicals present a limited amount of data on the reference intervals of biochemical indicators. Our test center has accumulated a data bank of such indicators that were determined in multiple-dose toxicity studies, which allowed us to conduct a retrospective analysis and review the available reference intervals. The calculation was based on observation data obtained in the period from January 2018 to December 2019. The determination of biochemical parameters in this period of time was carried out on the same equipment using the same methods. A retrospective analysis of the data was performed on 13 biochemical parameters of blood serum of three breeds of rabbits – New Zealand, chinchilla, white giant. The sample consisted of 127 females and 127 males, the age of the animals in the studies was 16-25 weeks (the weight of the animals was 3-5 kg). The article presents reference intervals for creatinine, urea, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, cholesterol, triglycerides, total protein, albumin, globulin, glucose, total bilirubin, and the albumin/globulin ratio. The necessity of creating intra-laboratory databases of reference intervals in each test center is justified. Interindividual variability was calculated for the specified biochemical parameters. The greatest inter-individual variability (more than 30%) was found for such indicators as alkaline phosphatase, triglycerides, cholesterol and total bilirubin. The use of retrospective data analysis allows us to implement the principles of 3Rs and get more correct data on a larger sample of laboratory animals. The analysis of the reference intervals obtained by us in comparison with the literature data, in general, showed their comparability, which can be considered as an additional confirmation of the satisfaction of the established intra-laboratory standards [Full text is available in Russian]. 

32. Matichin A.A., Faustova N.M., Kargopolceva D.R., Makarova M.N. Circadian fluctuation in plasma testosterone levels in adult male rats. Laboratory Animals for Science. – 2020, №2. https://doi.org/10.29296/2618723X-2020-02-04 Abstract. Testosterone is pleiotropic hormone. It plays an important role in human male and effect on various organ systems including brain activity, peripheral nerves, muscles, fatty and bone tissue, cardiovascular system, male genitals and reproductive system and it cause libido. In studies of the pharmacology activity of new medicines or pathological process in laboratory animals the level testosterone assay in biological fluids and tissues is the one of the important parameters. However it should be taken into account age, sex, endocrine state and also biomaterial sampling time and series of factors affecting on results of the testosterone level assay. Correct interpretation of experimental data is impossible without considering the biorhythm. In current study the data of level testosterone fluctuation in intact rats’ peripheral blood for 25 h (circadian rhythm). A significant increase in the level testosterone was recorded in most experimental animals during the period between 12:00 p.m. and 8:00 p.m.Maximal level of the hormone was 12 o’clock that was comparable with the literature. The testosterone data was sever variable. For example, level testosterone mean was 5,43±2,11 (SEM) nmol/L in 8:00 a.m. Testosterone variability was recorded in various experiments with animals and in clinical practice. In our study it was presented that high variability of the hormone in intact animals may result in the significant differences that make it difficult to interpret of data on therapeutic medicine effect. Thus, it is necessary to increase the animal number, conduct selection animals into experiment and also planning and controlling the biomaterial sampling time when planning an experiment which requires the level testosterone measuring [Full text is available in Russian].

33. Makarov V.G., Makarova M.N. New in the science and practice of preclinical research. Laboratory Animals for Science. – 2020, №2. https://doi.org/10.29296/2618723X-2020-02-07 Abstract. The article provides a brief description of some interesting publications about new research in the science and practice of preclinical research. The results of a study indicating the possibility of using gingival venopuncture as an alternative minimally traumatic method of blood sampling in Guinea pigs for hematological blood analysis are presented. Another publication gives a comparative assessment of the 6 most commonly used methods of blood sampling in mice (lateral incision of the tail; amputation of the tip of the tail; puncture of the hyoid, submandibular and subcutaneous veins; retrobulbar sinus puncture during anesthesia with isoflurane). An interesting study is the use of sliders for postoperative protection of rabbits. At the same time, it was shown that they are more successful than collars, both in terms of ensuring adequate social behavior of rabbits, and in terms of healing speed, less trauma to the site of the surgical incision, as well as – more economical. Another publication is devoted to the evaluation of a new system for keeping laboratory animals, the so-called “individually ventilated cells”, which have many advantages over conventional ventilation systems, allowing animals to reduce stress reactions, physiological and hormonal disorders that weaken the health of animals. Researchers dealing with oral and dental problems will be interested in a publication on the modeling of diet-induced generalized periodontitis in rats and the experimental evaluation of such a model [Full text is available in Russian].

34. Trofimets E.I., Makarova M.N., Katelnikova A.E., Kryshen K.L. Endotracheal administration to laboratory animals. Laboratory Animals for Science. – 2020, №2. https://doi.org/10.29296/2618723X-2020-02-08 Abstract. Any nonclinical study experiment of pharmaceuticals don’t perform without studied objects administration to laboratory animals. First of all the choice of administration method depends on the application method in clinical practice, and, in turn, is an important and necessary stage for further assessment of the studied objects effects on the target organs and the organism as a whole. There is increasing interest in targeted methods of administration due to the new medicines and dosage forms development with the targeted delivery to the organs and systems of the body. One of these methods is endotracheal administration, which is analogue of the inhalation method of drug administration in clinical practice. Delivery of pharmaceuticals directly to the lungs allows to achieve necessary therapeutic concentrations quickly in the target organ, reduce severity of its system and side effects, to avoid the effect of “first passage through the liver ” and drug destruction in the gastrointestinal tract. In laboratory practice this method of administration is interesting not only from the pharmacological activity and safety research study point of view, but also from the possibility of using this method for the respiratory system pathology induction. This paper presents an overview of the endotracheal method of administration to laboratory animals. This review discusses the most appropriate choice of anesthesia, procedure of administration, manipulation quality control, equipment, choice of vehicle, volume of administration and interspecific differences in the respiratory system physiological parameters (lung volume, length and diameter of the trachea) that need to be taken into account while planning the experiment with this type of administration. While study plan with endotracheal administration  to the laboratory animals preparing, it is necessary to take into account two important factors that affect the quality of manipulation: the volume of administration and the use of anesthesia during manipulation.  The active substance distribution in the lung tissue, undesirable effects development in the form of dosage loss and injury are depending of these factors. We have not found in the available literature information about the recommended and maximum allowable volumes for endotracheal administration to different types of animals. As a result of literature data analysis and our own experience we have proposed recommended and maximum volumes for endotracheal administration for various types of laboratory animals [Full text is available in Russian]. 

35. Makarov V.G., Makarova M.N. New in the science and practice of preclinical research. Report 2. Laboratory Animals for Science. – 2020, №3. https://doi.org/10.29296/2618723X-2020-03-01 Abstract. The article analyzes a number of important publications for 2019 for scientists engaged in biomedical research. Thus, a new model of melanoma in mice of the c-Kit-CreER line with tamoxifen is presented, which will provide an opportunity to test new chemotherapeutic and immunotherapy methods of treatment, as well as the potential health risks associated with them. In another publication, scientists from San Francisco who are studying the mechanisms of aging based on the study of the immunity of the naked mole rat, whose life span is ten times longer than that of ordinary rats, came to the conclusion about the significance of this high number of neutrophils, which play an important role in innate and adaptive immunity. An article by American scientists published in the journal of the American Association for Laboratory Animal Science in November 2019 is devoted to the analysis of the most commonly used methods of handling mice when manipulating them (cleaning cells, moving animals, etc.), such as the use of forceps (tweezers), gloved hands, plastic cups and special tunnels. In the July issue of the same journal, materials are provided to justify the possibility of increasing the interval of sanitary treatment of the upper parts (covers) of mouse cells to 90 days without compromising the sanitary condition and health of animals, in contrast to cells for rats, which must be treated at least once every 2 weeks. This reduces the labor cost of caring for mice and increases the service life of the equipment. The possibility of reducing the time of sanitary treatment of mouse cells in animal care programs is discussed in the September issue of the same journal. At the same time, the authors based on the Lean Six Sigma methodology (process optimization methodology) developed specific recommendations, such as: purchasing additional cells and racks for them; drawing up clear daily work schedules for each employee, taking into account specific stages of work; marking on the floor with colored tape areas of clean and dirty processes, as well as ways to move cells and racks in order to ensure that they do not intersect. This reduced the average cleaning time per rack of mouse cells by 35 minutes, and the time saved was used to improve the health and living conditions of laboratory animals [Full text is available in Russian].

36. Katelnikova A.E., Trofimets E.I., Matichin A.A., Faustova N.M., Gushchin Y.A., Makarova M.N. Dynamics of age changes of somatotropin concentration in blood plasma and morphometric parameters of laboratory female mice ovaries. Laboratory Animals for Science. – 2020, №3. https://doi.org/10.29296/2618723X-2020-03-07 Abstract. Preclinical studies its a significant part of the registration dossier, formed for the purpose of state registration of a new medicinal product (MP). The assessment of the endocrine status is not significantly defined in the requirements of regulatory documents for assessing the safety of a pharmaceutical agent. However, it is important to evaluate drugs being developed for the pharmaceutical market for their potential impact on a given system and compare them with the norms described in the literature. Somatotropin (STH, growth hormone) is one of the hormones, the assessment of the effect on which is important at the stage of preclinical studies of drugs. Growth hormone is responsible for bone growth, organ development, metabolism, energy homeostasis and also one of the factors regulating puberty and fertility in men and women. However, the norms of STH in laboratory animals used in preclinical studies are very little covered. In this study we assessed the level of somatotropin in the peripheral blood of intact laboratory outbred female mice aged 2 to 8 weeks. Also, a morphometric analysis state of the ovaries in animals was carried out within of this experiment. According to the results of the study, concentration of STH in the outbred female mice blood is from 0 to 3 ng / ml. The maximum concentration of STH in female mice blood plasma was recorded at the age of 3 weeks (2.79 ± 0.34 (SD) ng / ml). The level of the hormone decreased with increasing age of the animal, and by 6 weeks ages it was 0.76 ± 0.14 ng / ml. The experimental evidence the level of STH at the onset of puberty (approximately 12 days) and the average age of onset of puberty in female mice (from 8 to 13 years) are compatible. Based on the evaluating the morphometric parameters of ovaries, puberty occur in female mice at the age of 8 weeks. At 8 weeks, against of decrease in the level of STH, antral (tertiary) follicles and yellow bodies develop in the ovaries in all animals. It will be interested evaluation hormone level in uneven-aged outbredmale mice and other animal species including non-rodents (rabbits, minipigs, dogs) for more information and development of STH reference intervals [Full text is available in Russian].

37. Makarova M.N. Tekhnologicheskie protsessy v vivarii i pitomnike – kak obespechit’ kachestvo? : materialy VIII konferentsii assotsiatsii spetsialistov po laboratornym zhivotnym (Rus-LASA). Pushchino.1-3 October 2020.

38. Bondareva E.D. Risk-orientirovannyi podkhod k otsenke sanitarnogo blagopoluchiya vivariya i pitomnika, zdorov’ya laboratornykh zhivotnykh i cheloveka: materialy VIII konferentsii assotsiatsii spetsialistov po laboratornym zhivotnym (Rus-LASA). Pushchino.1-3 October 2020.

39. Makarova M.N. Ispol’zovanie ingalyatsionnoi anestezii dlya narkotizatsii i oksigenatsii gryzunov i negryzunov: materialy VIII konferentsii assotsiatsii spetsialistov po laboratornym zhivotnym (Rus-LASA). Pushchino.1-3 October 2020.

40. Il’inskaya M.A. Zootekhnicheskie osobennosti v soderzhanii laboratornykh negryzunov: materialy VIII konferentsii assotsiatsii spetsialistov po laboratornym zhivotnym (Rus-LASA). Pushchino.1-3 October 2020.