Common Laboratory animals-Experimental Pharmacology

1. Common Laboratory Animals -Bhumi

2. Laboratory animals • Laboratory animals are those animals that can be bred and reared in laboratory under suitable conditions. • Most common- rat, mice, hamster, guinea pig, rabbit • Large animals- dog, cat, monkey, frog, pigeon, etc. • Depending upon the special characteristics of animal and the study to be carried out  animal is selected. • The animal which is phylogenetically closer to men considered for the experiment

3. MOUSE • Biological Name : Mus musculus • Strains • -C57BL/6 mice • -Balb/C mice • -swiss albino mice(most commonly used) • Adult weight : 20-25gm • Suitable age for experiments : 1 month Balb/C mice

4. Characteristics • -smallest • -cheap • -easy to handle • Advantages • -short gestation period • -short lifespan • -small size • -low maintenance cost C57BL/6 mice

5. Experimental uses • toxicological studies(acute & subacute) • teratogenicity studies • bioassay of insulin • screening of analgesics & anticonvulsants • screening of chemotherapeutic agents • studies related to genetics and cancer research • study of drugs acting on central nervous system

6. RAT • Biological Name : Rattus norvegicus • Strains • -Albino • -Sprague-Dawley • -Wistar Kyoto • -Long evans • Adult weight : 200-250gm

7. Characteristics • small in size • warm-blooded rodent • vomiting centre is absent, so oral drugs can be given • gall bladder & tonsil are absent • greater sensitivity to most drugs • because of the absence of gall bladder, there is a continuous flow of bile into the intestine used to study of drugs acting on bile, cholesterol reabsorption, etc. • pancreas is diffuse difficult to produce pancreactomy • clear lining between fundus & pylorus gastric acid secretion is continuous

8. Wide head • Long ear • Tail length is lesser than body length • Resistant to infections • Longer & narrow head • Tail is longer than body length • Rapidly growing

9. Long Evans rat • black hooded rat •  cross between female albino & wild animal • Spontaneous hypertensive rat • For hypertension study and CVS disease study

10. Experimental uses • Psychopharmacological studies • Study pf analgesics and anticonvulsants • Bioassay of various hormones such as insulin, oxytocin, etc. • Study of estrus cycle, mating behaviour & lactation • Study on isolated tissue preparation • Chronic study on blood pressure • Gastric acid secretion studies • Study of hepatotoxic compound • Acute & chronic toxicity studies • Study on mast cells • Rat brain tissue is extensively employed in radio-receptor studies

11. GUINEA PIG • Biological Name : Cavia porcellus • Strains • -Dunkin Hartley • -Starin-13 • Adult weight : 400-600gm

12. Characteristics • Docile animal • Herbivores • Requires exogenous ascorbic acid in diet • Warm blooded rodent • Sensitive cochlea • Highly susceptible to tuberculosis & anaphylaxis • Highly sensitive to histamine & penicillin

13. Experimental uses • Evaluation of bronchodilators • Anaphylactic & immunological studies • Study of histamines & antihistamines • Bioassay of digitalis • Study of tuberculosis & ascorbic acid metabolism • Evaluation of local anaesthetics • Hearing experiments • Study on isolated tissues like ileum, trachea, vas deferens

14. FROG • Biological Name : Rana tigrina • Strains • -Rana esculenta • -Rana pipiens • -Rana temporaria • Adult weight : 50-100gm

15. Characteristics • Cold blooded amphibian • 3 chambered heart  two atrium & one ventricle • Highly permeable skin(breathe largely through their skin) • Camouflage defensive mechanism • Experimental uses • Screening of certain drugs like anaesthetics • To study the effect of drug acting on CNS, neuromuscular junction & heart • Study of isolated tissue like rectus, abdominis muscle, heart, sciatic nerve preparation, etc.

16. RABBIT • Biological Name : Oryctolagus cuniculus • Strains • -New Zealand white(commonly used) • -Himalayan black • Adult weight : 1.5-3kg

17. Characteristics • Docile animal • Large ears • Big eyes • Warm blooded mammalian • Some strains are resistant to effective of atropine because they have higher concentration of atropinase enzyme in their blood • Skin is sensitive to irritation • Can’t vomit • Sensitive to histamine • Secretion of leutenising hormone(LH) in female New Zealand white rabbit

18. Experimental uses • Pyrogen testing • Bioassay of antidiabetic and sex hormones • Irritancy tests • Study of drug used in glaucoma • Pharmacokinetic studies • To test toxic effects of cosmetics • Good model for the production of antibodies & antiserum • Screening of agents affecting capillary permeability Himalayan black rabbit

19. HAMSTER • Biological Name : Mesocriceius auratus & Cricetulus griseus • Species • -Golden or Syrian hamster • -Chinese hamster • -Winter white hamster

20. Characteristics • Short body • Short legs and tail • Loose skin & skin covered with dense short soft fur • Cheeks pouches are prominent & extend upto shoulder region • Cheeks pouches don’t have lymphatic drainage ideal site for tissue transplants

21. Experimental uses • Research on diabetes mellitus • Bioassay of prostaglandins • Research related to virology, immunology & implantation studies • Research on carcinogenic & mutagenic agents(Armenian hamster) • For highly concentrated & prolonged smoke inhalation studies( European hamster) • Chinese hamsters have low chromosome number making it useful for cytological investigations, genetics, tissue culture & radiation research

22. MONKEY • Biological Name : Macaca mulatta • Characteristics • Structurally & functionally similar to men • Uterus resembles human & exhibiting regular menstrual periods • Experimental uses • Psychopharmacological studies • Pharmacokinetic studies • Primate model to study drug metabolism • Study of drugs acting on CNS, CVS, GIT & fertility

23. CAT • Biological Name : Felis catus • Characteristics • Has distinct nictitating membrane • Experimental uses • Used in cardiovascular, behavioural & biomedical research • Used in screening of ganglionic drugs • Studying the transmission of vitamins & minerals to foetus & newborn • Used in neuropharmacology, toxicology, oncology & chromosomal abnormality studies

24. GERBIL • Biological Name : Meriones unguiculatus • Also known as “sand rat” & “jirds” • Have length between mice & rats • Characteristics • Easy to handle • Mild and quite nature • Hearing curve similar to human • Experimental uses • Used in stroke, epilepsy, auditory studies • Used in bacterial infections, lipid metabolism, heart disease studies

25. DOG • Biological Name : Canis familiaris • Characteristics • Small alimentary tract • Easily get trained • Experimental uses • Study of anti-arrhythmic, cardiovascular & autonomic drugs • Good model for diabetes mellitus, reproduction, ulcerative colitis, open heart surgery, organ transplantation, CNS

26. Beagles dog Mongrel dog • This both dogs are most preferred for experimental purpose due to • Manageable size • Moderate length of hair coat • Docile nature • Easy to handle • Stomach & intestinal tract resembles human

27. PIG • Biological Name : Sus scrofa domestica • Characteristics • Less hairy skin • Susceptible to bronchitis & pneumonia • Experimental uses • Study of skin related studies • Important model in cardiovascular research such as atherosclerosis, myocardial infarction, etc.

28. CHICKEN • Biological Name : Gallus domesticus • Characteristics • Ease of availability • Experimental uses • Study on toxicology & pharmacology behaviour • Studying avian diseases • Important models developed in chicken are chick comb method, chicken blood pressure measurement, heart rate, EEG, etc.

29. PIGEON • Biological Name : Columbia livia • Experimental uses • Study of antiemetics • Used for standardization of cardiac glycosides • Bioassay of prolactin • Used for screening on intravenous anaesthetics

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