common lab animals.pptx

common laboratory animals used in preclinical studies. it is useful for pharmacy and professionals who handle animals and experiment with animals.

1. COMMON LABORATORY ANIMALS

2. Mouse ( mus musculus) 95% of lab animals Features Smallest laboratory animal Short reproductive cycle Ample information of anatomy, genetics, biology Organ system similar to humans – shape, structure, physiology

3. Long loops of henle - concentrated urine, 1-2 drop Large amount of protein in urine Only 2 types of teeth- incisors and molars Stomach – 2 compartments Proximal- keratinized Distal- glandular Short rectum- prone to prolapse

4. Poor eyesight , color blind Hearing range – 0.5 to 120kHz Mice can swim- but avoid swimming Aggression – In group housed male/female mice Wounds can cause blood loss, abscess Most aggressive strain – BALB/c, outbred swiss To prevent aggression – grouping of mice before puberty adequate space removal of dominant animals

5. Barbering ( Dalila effect) - A behavior in which a dominant mouse will trim, by chewing, the hair or whiskers of other mice in the cage.

6. No sweat glands- In hot climate - increase blood flow to ears to maximize heat loss or move to burrows. Non-shivering thermogenesis Reproductive biology Females – Similar to humans 5 pairs of mammary glands Males – Large seminal vesicle, Ejaculate - coagulatum /copulatory plug

7. Breed continuously throughout the year Reproductive potential affected by- noise, diet, light cycles, - population density or cage environment.

8. Pups- hairless, blind, deaf- pinkies Detemination of sex- Anogenital distance- longer in males Presence/absence of testicles or mammary glands in sexually mature mice

9. Behaviour Social creature – easy to group and house Communicate through pheromones – Social organization Role in reproduction Whitten effect Bruce effect Nocturnal animals Prey species – avoid open spaces, wall hugging

10. Signs of ill- health Weight loss/obesity Lethargy Anorexia Obesity Diarrhea Scruffiness/ruffled coats Abnormal breathing Discoloration Masses/swelling Abnormal gait

11. Use in research Toxicity studies Insulin assays Analgesic assay Screening of chemotherapeutic agents Genetics and cancer research Teratogenicity testing

12. Breeding types and methods Model Generation Examples Inbred strains 20 or morec onsecutive generations of sister and brother or parent and offspring matings BALB/c, C3H, C57BL/6, CBA, DBA/2, C57BL/10, AKR, A, 129, SJL Outbred strains Deliberate mating of unrelated animals Swiss, webstar , CD-1, ICR Spontaneous mutant Strains that have bred to conserve phenotypical characteristics that were due to spontaneous genetic mutation nonobese diabetic (NOD) Genetically engineered Knock in /knock out Mice where genes have been turned on or off Transgenic mice Mice where a gene from an unrelated species has been inserted into the genome

13. Breeding Methods Hand mating – male and female bought together for brief period of time and then separated once mating is over eg : rabbit and hamster 2. Pair mating – one male mated with one female and left together for rest of their breeding life. Eg mice - pregnant female separated prior to delivery in rats Trio mating – one male mated with two females. Harem mating – four females regularly mated with one male. Female isolated soon after pregnancy.

14. The Rat Most common – albino rat Relatively smaller size Known genetic background Short generation time Known microbial status Most standardised of all laboratory animals Wistar – quiet, resistant to infection - tail less than body length wistar Sprague dawley

15. No vomiting centre No tonsil or gall bladder Diffuse pancreas Omnivorous – resembles man nutritionally Oestrous cycle Stage Duration Type of vaginal cell Oestrous (sexual receptivity) 12hr Cornified epithelium Met- oestrous 20hr Many leucocytes, few cornified Di- oestrous 60-70hr Mainly leucocytes Pro- oestrous 12hr Nucleated epithelial cells singly/sheets

16. Normal behavior Nocturnal species Nesting behaviour Emit alarm vocalization in distress/pain

17. Reproductive biology Male – Lack of closure of inguinal rings - Four-lobed prostate - Bihorned shape of the closely associated coagulating gland and seminal vesicles

18. Female Duplex uterus Pups – Hairless, blind, deaf Nesting material for thermoregulation

19. Use in research Trained easily- psychopharmacological tests Study of oestrous cycle, mating behaviour and lactation Shay method- antiulcer drugs evaluation Study of analgesic agents Toxicity studies 24 hr old rat = 6month old infant Study of physiology of liver Teratogenicity , carcinogenicity

20. THE RABBIT (Oryctolagus cuniculus) Features (similar to other mammals except) Skin- thin and fragile No pads on feet No sweat glands Smaller skeleton mass (8%only) Female rabbit (doe) – dew lap – large skin fold under chin Obligate nose breathers

21. Ears – long - better hearing - blood collection Central ear artery (black) , marginal ear vein ( red) - thermoregulation

22. AV valve- bicuspid Purkinjee fibers- similar to humans Teeth – all open rooted no canines peg teeth- second set of incisors behind first Obligate herbivore Require high fibre diet

23. Reproductive biology Sexual maturity – 5-7 months Females – 8-10 nipples Induced ovulators no defined estrous cycle Males (bucks)- open inguinal rings Birthing occurs at early morning hours Newborns (kits)- deaf , blind 7-10 days- hear and see suckle once a day at dark hours weaning- 5-8 weeks

24. Behavior Social, nocturnal creatures Scent marking (chin scent glands) Barbering by dominant animals Thump back feet when frightened/scream loud piercing noise Relaxed- purring sound Stereotypic behaviour – bar chewing, self-barbering, nose sliding, head swaying Animals with stereotyping behaviour do not make good research animal

25. In pain – decreased appetite (first sign) bruxism(grinding of teeth) dull/inactive Night feces - caecotrophs

26. GUINEA PIGS ( Cavia porcellus ) Rodents related to porcupines Weight- 700-1200g Prone to scurvy – external vit. C Higly sensitive to histamine (1000 times )

27. Use in research Louis Pasteur – First rabies vaccine Most commonly used – NZW rabbit (New Zealand White) Teratogenicity testing Widely used in hypersensitivity, immune response and anaphylactic shock Other- atherosclerosis, osteoporosis, ocular surgical implantation of biomedical devices Used for model of infectious disease- tuberculosis, legionnaire’s disease STD, Staph. Aureus induced nosocomial infections.

28. ZEBRA FISH (Danio rerio) Fresh water fish Adult 4-5 cm Males- larger anal fin Life span- 1 year Reside in shallow streams, season waters Sexual maturity- 2 months 150-400 eggs/clutch

29. Features Small size Ease to keeping large numbers Frequent spawning Large egg clutches Translucent non-adherent eggs Complex sequencing of genome 70% zebrafish genes have atleast one orthologous human gene

30. THE HAMSTER Commonly used species- Syrian and Golden hamster 4 toes front, five toes back Prominent ears, pigmented Prominent check pouch – site of implantation of homo/hetero-grafts Cheek pouch is capable of accepting many tumor grafts

31. Use in research Golden hamster – Virology, cancer and nutrition research Genetics, toxicology and reproductive physiology Chinese hamster- Diabetes (beta- cells deficient/defective) Low chromosome number(22) – cytological investigations, genetics, tissue culture and radiation reasearch

32. THE DOG Short stomach and long intestine- as in humans Can be trained to carry stomach cannula Use in research Anaesthetised dog – drugs affecting blood pressure Circulation studies on unanaesthetised animals Descrete pancreas – diabetes study Study of gastric secretions.

33. THE MONKEY Highest order of mammals Closely resemble men - Human type uterus, Regular menstrual period Brain structure Use in research Psychopharmacological agents Virology, parasitology, immunology Immunosuppression, nutrition Reproduction

34. THE CAT Use in research Physiology of circulatory and neuromuscular systems Drugs affecting blood pressure Contraction of nictitating membrane- investigation of ganglionic blocking action of drugs Study of central nerve system Ability to produce methemoglobinemia- toxicity studies

35. THE FROG Absorb water through skin Frog heart – more sensitive of adrenaline Action of drugs on CNS, heart, and neuromuscular junction Diagnosis of pregnancy- male frog test Retinal toxicity of drugs

36. Important physiological data of laboratory animals Parameter Rabbit Guinea pig Rat Mouse Hamster Daily food (g) 150-300 40-50 10-20 4-5 10-14 HR (/min) 130-300 260-400 300-500 330-780 318-412 RR (/min) 38-60 70-104 65-180 84-230 33-127 Tidal vol (ml) 19-24 1.8 1.5 0.1-0.23 0.83 Systolic 110 77 116 113 108 Diastolic 80 47 90 81 77 Hb (g/100ml) 8-15 8-15 12-17 10-19 16.8 RBC 4.5-7.5 5-6 7.2-9.6 4.9-12.5 7.5 WBC 6-13 4-11 6-12 4-12 7.6 Blood volume (%body weight) 4-8 6-12 6-7 7-9 6-9

37. Parameter Rabbit Guinea pig Rat Mouse Golden hamster Chinese hamster Adult wt (g) 1500-5000 800 250 20-40 80-90 35-40 Av. Life span( yrs ) 4-6 3-5 2-3 1.5-2.5 2-3 2-3 Average age suitable for experiment 6 3 1.5 0.75 1 1 Average age of first mating(months) 6-7 3 2.5-3 1.5-2 2-3 2-3 Breeding habits (1male:female) 1 6 5 3 1 1 Gestational period 31 68 21-23 19-21 16 21 Litter size 6-8 3-4 8-10 6-12 5-7 4-5 Weaning (days) 45 14-21 21 21 20-25 21 Weight at weaning(g) 600-1500 160-230 35-45 10-14 30-40 6-8 Litter/year 4 4 6 8-10 - 7 Duration of sexual life(months) 36 24 12 12 - 12 Rest period between mating (female) 20 15 15 15 - 15

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