Guinea Pig as an Experimental Animal by Dr. Vyaktika Shree.pptx

guinea pig as an exerimental anima

1. Guinea Pig as an Experimental Animal Dr. Vyaktika Shree 3 rd Year Junior Resident Department of Pharmacology and Therapeutics King George’s Medical University, Lucknow, UP, India- 226003 Email: [email protected] 28-12-2024 Dr. Vyaktika Shree 1

2. Learning Objectives Characteristics Handling Diet Why Guinea pig ? Advantages as Experimental Model Limitations Ethical Consideration 28-12-2024 Dr. Vyaktika Shree 2

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4. Introduction Docile & humble animal Cavia porcellus 19th and early 20th centuries guinea pigs were crucial Dr. Robert Koch developed his 5 postulates of infectious disease etiology Studied tuberculosis and diphtheria , won Nobel Prize 28-12-2024 Dr. Vyaktika Shree 4

5. Characteristics 28-12-2024 Dr. Vyaktika Shree 5 Weight (gm) 600-1200 Life Span (year) 4 to 8 Food intake (g/day) 6/100 g Water intake (ml/day) 10/100g Gestation period (days) 59 to 72 Heart rate (min) 230-380 Blood pressure systole (mmHg) 80-94 Diastole (mmHg) 55-58 Respiratory rate (min) 42-104 Animal house temperature (°C) 18 to 26

6. Newborn guinea pig can eat solid food by the fifth day and may be weaned by 2 weeks Young guinea pig are best mated after 3 months of age Maturing is slow in male as compared with female Coitus generally occurs at night and that followed by polygamous group mating Duration of estrous cycle will range from 13-20 days an average of 16 days further divided into the other stages such as proestrus, estrus, metestrus and diestrus 28-12-2024 Dr. Vyaktika Shree 6

7. Sex Determination Both male and female guinea pigs display similar anogenital distances. F emale has detectable pink nipple at either side, a separate urethral orifice, a vaginal membrane, a perineal sac Male has a penis, a larger perineal sac Penis lies just under the skin and can be inverted with gentle pressure. Testes and penis are palpable in adults 28-12-2024 Dr. Vyaktika Shree 7

8. Male Guinea Pig 28-12-2024 Dr. Vyaktika Shree 8 Nipple Perineal Sac Urethra Penis Larger Perineal Sac Female Guinea Pig

9. Handling of Guinea Pig Method 1 O ne hand under the chest , other supporting its hindquarters

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11. METHOD 2 One hand by holding its hind quarters

12. Herbivorous and eats green foods, seeds and roots Essential to add vitamin C (ascorbic acid) , not able to synthesize the required vitamin C daily If provided greens , vitamin C should be given at the rate of 1gm/L of drinking water on a weekly basis If laboratories feed is provided with a readymade chow diet, then vitamin C should be added in the dose of 200 mg/L daily 28-12-2024 Dr. Vyaktika Shree 12 Food?

13. 28-12-2024 Dr. Vyaktika Shree 13 WHY ME? Physiological similarity to humans- immune response and pathogenesis Naturally sensitive to various bacterial and viral infections Nutritional similarity- like humans, guinea pigs cannot synthesize Vitamin C and rely on dietary intake, making them a model for scurvy and ascorbic acid metabolism studies Ethical and practical considerations- small, easy to handle, and breed well in laboratory conditions, making them convenient for controlled experiments Mutation of GULO gene

14. Importance in Research Immunology and Respiratory Models eg. asthma and COPD Infectious Disease Research eg. TB , STD’s and other bacterial infections (pulmonary, ocular, gastrointestinal) Widely used for hypersensitivity, anaphylactic shock and ascorbic acid metabolism studies Screening local anesthetics and developing treatments/vaccines for diseases with similar pathogenesis in humans 28-12-2024 Dr. Vyaktika Shree 14

15. Advantages as Model Guinea pigs are considered most suitable experimental animals for local toxicity test Highly sensitive to histamine (1000 times more sensitive than rat) Serum contains an enzyme asparaginase , which shows antileukemic action Very susceptible to tuberculosis and anaphylactic shock Highly sensitive to penicillin (100-1000 times more than rat) 28-12-2024 Dr. Vyaktika Shree 15

16. Limitations Ethical Concerns Use of live animals raises ethical questions Strict compliance with animal welfare regulations is needed Specialized Care Requirements Need for Vitamin C supplementation to prevent scurvy Susceptibility to stress and infections 28-12-2024 Dr. Vyaktika Shree 16

17. Limited Genetic Tools Compared to mice, guinea pigs have fewer genetic modification tools Limits applicability in genetic research Cost and Maintenance Higher costs of housing and maintenance than smaller models like mice Longer breeding cycles 28-12-2024 Dr. Vyaktika Shree 17

18. Ethical Considerations Importance of Humane Treatment Ensuring ethical care (5R’s of animal ethics) of guinea pigs in research is essential for credible and reproducible results Emphasis on minimizing stress, proper housing, and feeding to ensure well-being 28-12-2024 Dr. Vyaktika Shree 18 Replacement Reduction Refinement Reuse Rehabilitation

19. Compliance with Animal Welfare Regulations in India Governed by the CCSEA Ethical guidelines require prior approval from IAEC Practices align with global standards like IACUC 28-12-2024 Dr. Vyaktika Shree 19 Committee for Control and Supervision of Experiments on Animals (PCA Act of 1960) Institutional Animal Ethics Committees Institutional Animal Care and Use Committee Ministry of Fisheries, Animal Husbandry and Dairying ( MoFAH&D )

20. Summary Herbivorous, require Vitamin C supplementation, and mature slower in males Estrous cycle averages 16 days; males and females have distinct genital characteristics Immune response and nutritional needs mimic humans; ideal for scurvy and infectious disease models Used for immunology, respiratory diseases, hypersensitivity, toxicity and vaccine development Sensitive to stress, infections and drugs like penicillin; require ethical care and specialized diets 28-12-2024 Dr. Vyaktika Shree 20

21. References Medhi B, Prakash A. Introduction to Experimental Pharmacology. In: Practical Manual of Experimental and Clinical Pharmacology. 2nd ed. New Delhi: Jaypee Brothers Medical Publishers; 2017. p. 9-10 Gupta SK. Introduction to Experimental Pharmacology. In: Drug Screening Methods. 2nd ed. New Delhi: Jaypee Brothers Medical Publishers; 2009 Padilla-Carlin DJ, McMurray DN, Hickey AJ. The guinea pig as a model of infectious diseases. Comp Med. 2008 Aug;58(4):324-40. PMID: 18724774; PMCID: PMC2706043 28-12-2024 Dr. Vyaktika Shree 21

22. Why are guinea pigs considered suitable experimental animals for studying nutritional deficiencies such as scurvy or respiratory and infectious diseases? What unique sensitivities and enzymes in guinea pigs are utilized in research? How will you differentiate between male and female guinea pig? How will you handle guinea pig? 28-12-2024 Dr. Vyaktika Shree 22 Queries? Let me ask some questions Comments?

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