BASICS OF EXPERIMENTAL PHARMACOLOGY

Transcription

1 BASICS OF EXPERIMENTAL PHARMACOLOGY

2 PHARMACOLOGY is the science which deals with study of drugs EXPERIMENTAL PHARMACOLOGY: deals with effect of various pharmacological agents studied on different animal species AIMS : Find out the therapeutic agent suitable for human use Study the toxicity of the drugs Study the mechanism and site of action of drugs Pharmacology Discovery of new drugs or to study the actions of existing drugs Preclinical Two ways 1) Intact animal study invivo 2) isolated organ study invitro Clinical Phase -1,2,3,4

3 Experimental pharmacology great imp Experimenter should take outmost care Sacrificing - humane Euthanasia painless killing Laboratory animals breaded and handled in laboratory Mice Rat Guinea pig Rabbits species Rattus norvegicus RAT Wister starin is commonly used Other strains

4 Wistar rat Sprague Dawley rat Biobreeding rat Long-Evans rat Zucker rat Hairless rats RCS rats Shaking rat Kawasaki Genetically modified rats Wistar rat Hairless rats Sprague Dawley rat Zucker rat

5 ADVANTAGES AND CHARACTERISTICS small in size drug to be tested required in small quantity vomiting center is absent oral administration can be done gall bladder and tonsils are absent Continuous flow of bile into intestine This facilitates the study of the drugs acting on bile, cholesterol reabsorbing ect pancreas are diffused therefore difficult to produce panereactomy stomach, fundus and pyloric parts are clear lining between them Gastric acid secretion is continuous

6 EXPERIMENTAL USE psychopharmacological studies study of analgesics and anticonvulsants bioassay of various hormones, such as insulin, oxytocin, vasopressin Study of estrus cycle, mating behavior and lactation isolated tissue pre s chronic study Gastric acid secretion hepatotoxicity studies study on mast cells

7 MICE ( Mus musculus) ADVANTAGES Smallest Easy to handle Cheap Less drug required EXPERIMENTAL USES toxicological studies teratogenicity studies bioassay of insulin screening of analgesic and anticonvulsant Screening of chemotherapeutic agents studies related to genetics and cancer research drugs action on CNS Swiss albino mice are commonly used species Other strains are Balb/C and C-57

8 GUINEA PIGS ( CAVIA PORCELLUS ) docile animals highly susceptible to TB and anaphylaxis Highly sensitive to histamine, penicillin Required exogenous vit c in diet EXPERIMENTAL USES evaluation of bronchodilators anaphylactic and immunological studies study of histamine and antihistamines bioassay of digitalis evaluation of local anesthetics hearing experiments because of sensitive cochlea isolated tissues especially ileum, heart study on TB and ascorbic acid metabolism

9 RABBITS (Lupas cuniculus) Docile animal New Zealand white strains are widely used it has huge caceum and long appendix enzyme atropine esterase is present in rabbit liver and plasma so it can tolerate large doses of belladona (atropine) EXPERIMENTAL USES pyrogen testing bioassay of anti-diabetic, curareform drugs and sex hormones screening of agents affecting capillary permeability drugs used in glaucoma pharmacokinetic studies studies related to antifertility agents isolated preparations like heart, duodenum, ileum, pre s study on local anaestetics Study on miotic and mydratics

10 FROGS (RANA TIGRINA) Most commonly used in physiology, pharmacology and toxicoloty used before 200 years amphibian animal safe to handle Cannot breed in lab EXPERIMENTAL USES isolated preparations, heart, rectus abdominis muscle drugs acting on CNS Drugs acting on NMJ

11