LABORATORY ANIMALS FOR THE SRCEENING OF AYURVEDIC MEDICINES

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Dr.M.Srinivas Naik

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LABORATORY ANIMALS FOR THE SRCEENING OF AYURVEDIC MEDICINES:

LABORATORY ANIMALS FOR THE SRCEENING OF AYURVEDIC MEDICINES DR. K. SHANKAR RAO ASSOCIATE PROFESSOR DEPT. OF RASASHASTRA & BHAISHAJYA KALPANA NATIONAL INSTITUTE OF AYURVEDA JAIPUR. Ph: 09887181781 (M) E-mail: raokshankar@yahoo.co.in

INTRODUCTION :

INTRODUCTION Animal experimentation is fundamental to the biomedical sciences for the advancement of basic understanding of the nature of life and the mechanisms of specific vital processes, and also for the improvement of methods of : Prevention Diagnosis & Treatment of diseases both in man & animals.

WHY ANIMALS USED:

WHY ANIMALS USED Animals are models of analogues Testing the potency Safety of biological substances used in human For determining the toxicity of the rapidly growing number of synthetic substances that never existed before in nature and which may represent a hazard to health.

ANIMAL ETHICS:

ANIMAL ETHICS Reduction Refinement Replacement & Rehabilitation

MONITORING FACTORS:

MONITORING FACTORS

PHYSICAL AND ENVIRONMENTAL FACTORS:

PHYSICAL AND ENVIRONMENTAL FACTORS Room Temperature : 1. Temperature variations leads to changes in behaviour (e.g., shivering, huddling) 2. Metabolic rate ( ↑ food consumption & body heat production). These changes could affect several metabolic processes including drug metabolism. 3. Animal room temperature limited to +/- 22 º C. 4. Maintain cage (microclimate) environment.

CAGES :

CAGES

Contd..:

Contd.. Fig.

THE HOUSE :

THE HOUSE The amount of space per animal The number of animals per cage may influence an animal's response in an experiment. Number of rodents per cage affects the stress level (either isolation or crowding), and their growth. Animals should be housed in small groups to minimize stress, and for social enrichment. Ensure feed is not wasted

RELATIVE HUMIDITY (RH) :

RELATIVE HUMIDITY (RH) An experimental animal room should be maintained in the range of 40-70% RH because: This is most comfortable level for the animals Micro-organisms have the lowest survivability Air borne allergens are lower at this level than when it is drier in the room - RH of less than 40% can cause ringtail in young, and result in respiratory irritation.

RH:

RH .

Ring tail disease:

Ring tail disease

LIGHT :

LIGHT The day/night cycle The intensity of the lights and the wavelength. Timer control of day/night cycle is necessary to maintain a consistent diurnal rhythm in the animal's metabolic state. Albino rodents in particular experience retinal damage when room light intensities are above 300 Lux.

Contd…:

Contd… Light "Pollution" Can Alter Tumour Growth Rates

VENTILLATION:

VENTILLATION Recommended air exchange rates in animal rooms are 15-20 air changes per hour. Are necessary to remove animal generated heat, ammonia, carbon dioxide, and airborne particles (dust and allergens).

Contd..:

Contd.. fig.

NOISE:

NOISE The fact that loud "buzzer" noises may induce seizures in young rodents (this has been used to create a model of audiogenic seizures) is well known. Both intensity and sound frequency are important. Rodents and some other animals are particularly sensitive to ultrasonic frequencies, ones that we may not even be aware of since they are beyond the range of the human ear. Low frequency and other noises, for example from nearby construction, may also disturb the animals.

FEEDS AND WATER :

FEEDS AND WATER (certified) feeds. Water usually municipal water with perhaps some treatment in the animal facility. If special dietary or water requirements are needed for the research project, the researcher must inform the animal facility management and laboratory animal technical staff.

ANIMAL BEDDING:

ANIMAL BEDDING Paddy Husk Cellulose wadding Saw dust Stredded papers Peat mass litter Corn o Cob The phenomenon of resins in softwood bedding (e.g., cedar shavings) activating some of the hepatic enzyme systems (P450 enzymes) is well known. This may complicate results if the experimental outcome is related to hepatic enzyme activity.

ANIMAL CARE AND HANDLING FACTORS :

ANIMAL CARE AND HANDLING FACTORS Animal Stress: from many different sources can affect the animal's physiology, biochemistry and behaviour. Sources of stress: Handling Transportation Stress

THE MOUSE (MUS MUSCULUS):

THE MOUSE (MUS MUSCULUS )

:

MANIFOLD VARIATIONS CONVENIENT SIZE HIGH FERTILITY SHORT GESTATION PERIOD EASE OF MAINTENANCE RESISTANCE TO DIFFERENT INFECTIONS EXEMPLIFICATION OF MANY DISEASES THAT AFFECT MANKIND CHARACTERISTICS

FEATURES:

FEATURES Slender body Smooth Hair coat Wt. 35 – 40 gms. Nipples : 05 pairs (3+2) Housing: 25x30x15 cm Puberty : 4-6 weeks Mating done at : 60 days Estrus cycle : (5) with 4 days intervals Gestation period : 21 days

STRAINS:

STRAINS 1. Balb’c’ : Low mammary tumor 2. C3H : Higher Ca prone 3. CBA : Lower the mammary tumors 4. DBA/2 : “ 5. C57 (BL) : Has db/db mutations (resistant to audiogenic seizures 6. SJL : Developed all types of tumours 7. AKR : Leukamia highest incidence 8. A/2G : Resistance to Influenaza 9. HRS : Thymic + Hairless + Leukemia 10.Nude : A Thymic + T cell altered, auto immune

MODULES:

MODULES Studies More than 85% 1. Mineral toxicities ex. Hg, Zn & Pb etc.. 2. Diet induced obesity and Diabetes 3. Effects of diet on gall stone 4. Production of Exp. Carcinogenesis. 5. Nutrition, Infection, 6. Effects of malnutrition on immunity 7. Pesticides / Aflatoxin toxicities

RAT:

RAT .

RAT ( Rattus Norvegicus):

RAT ( Rattus Norvegicus) 1. Wide head 2. Long ears 3. Tail length less than body length 4. Nipples 6 pairs 5. Wt. 350- 900 gms 6. Cage space: 1700 Sq. Cm. 7. Estrus: 6-7 weeks 8. FM: 90-120 days 9. Gestation period : 21 days

STRAINS:

STRAINS 1. Wistar 2. Sprague Dawly 3. Holtzman : Various tumors 4. CFY : for Ca 5. Fisher 344 : 6. W. Kyoto (JP) : 7. GOTE : lean but diabetic 8. W. NIN Ob/Ob : obese but glucose tolerance 9. W. NIN Gr/Ob : Ob but impaired glucose tolerance 10.Kollesky Rat : Obese but HT, CVS

MODULES:

MODULES > Nutritional Research > complex studies > Biological value of proteins & effects of starvation > Micronutrient deficiencies > The 5 day old rat, is an appropriate model for human new born in terms brain maturation > A technique involving ligation of one uterine artery on the 17 th day of gestation has used to develop a model for human low birth weight baby. > An animal model for rickets in weaning rats can be developed by maintaining animals on low phosphate, high calcium vit. D free diet for two weeks.

Contd..:

Contd.. > Many of the mineral deficiencies found in humans can be mimicked in Rats: Fe, Mg, Mn, Cr, Zn Na, Ni, Ni, Sn, Se & Vit E. > Essential fatty acids deficiency can be produced in Rats by feeding a free fat diet suplemented with 4% tri-palmitin for 8-12 weeks from the time of weaning. > Fatty liver and cirrhosis have been recognized as sequelae of excessive intake of alcohol and its accompanying nutritional problems (Patho & Bio-chem) > Methyl Hg poisoning resembling Minimata disease in humans mimicked in rats.

RAT cannot be a model:

RAT cannot be a model 1. Studies on Vit. C deficiency 2. Gall bladder stone

HAMSTER (Mesocricetus Auratus):

HAMSTER (Mesocricetus Auratus) .

FEATURES:

FEATURES 1. Chunky body 2. Diminisive fluffy tail 3. Large amount of loose skin 4. 12-14 Mammary glands 5. Wt. 90-175 gms. 6. Housing : 17x17x25 Cm. 7. Puberty 4-6 weeks 8. Gestation period 16 days 9. Presence of Cheek pouches

SPECIES:

SPECIES 1. Chinese Hamster (Cricetulus grisseus) 2. European “ (Cricetus cricetus) 3. American “ (Cricetulus Migratorius) 4. Caucassion “ (Mesocricetus branditi) 5. Hairy footed “ (Phodophus sugorus) * C. Hamster: Incidence of spontaneous D.M *Deficiency in β -cells due to low chromosomal (22) * Cytological & genetic res.

MODULES:

MODULES Higher requirement of pantothenic acid & Riboflavin Useful in study of B-complex High tolerance of Se. (Se. antogonises fl. And increases the incidence of dental caries in Human as well as animal) likely to be very useful for studying of this condition. Model for diet induced cholelithiasis (gall stones form quickly (2-4 weeks) in this sp.) Infectious diseases like- P.Pneumonia , diptheria, T.B. Rabis & Viral influenza etc.. Pouch- Ca & Immunological Res.

Contd..:

Contd.. 1. Teratogenecity 2. Aflatoxin 3. Diabetes 4. Tobaco induced Cancer etc..

GUINEA PIG (Cavia Porcellus):

GUINEA PIG (Cavia Porcellus)

G.Pig :

G.Pig Galacto norlactone dehydrogenase (Absence) ↓ Glucuronolactone ↓ Vit.’C’ (Scurvy & collagen synthesis) * Requirement of Pantothenic acid →Abortion

MODEL:

MODEL Carbohydrate Lipid Metabolism Protein deficiency Trace elemental studies Pregnancy toxaemia or Ketosis is quite common in late pregnancy due to in adequate diet, fasting, obesity and lack of exercise. High susceptible to T.B, Diptheria Sensitivity to chlorinated byphenyls

RABBIT (Oryctolagus cuniculus):

RABBIT (Oryctolagus cuniculus) .

Contd..:

Contd.. Specified micro flora takes care of most vit. B- complex Poor converter of tryptophan to Niacin - Anorexia Studies on Vit A & Nervous system disturbances Susceptible to hypoparathyroidism & E and D Best module Atherosclerosis WHHL: low density lipo protein cholesterol receptors New zealand white rabbit : Hypoinsulinaemia D.M.1 Induced pregnancy -Teretogenecity

Spontaneous models:

Spontaneous models Spontaneous models - often called "natural" models. These include naturally occurring animal diseases or conditions that correspond to the same diseases or conditions in humans. Diabetes, hypertension, arthritis, immune deficiencies are just a few examples. Many hundreds of animal strains/stocks with inherited conditions have been characterized and conserved.

Experimental models:

Experimental models > Experimental models are models in which a condition or disease is experimentally reproduced by the scientist. >Ex. Producing diabetes using the chemical streptozotocin to damage the insulin producing cells in the pancreas. >Using a chemical carcinogen to produce a certain type of cancer. >Producing a stroke model through surgery.

Genetically modified models:

Genetically modified models Are a special group of induced animal models, involving manipulation of the animal's genetic code to produce the condition that the scientist wants to study. Genetically modified animals may carry inserted foreign DNA in their genome, or have genes replaced or removed ("knock-out" models). These models can help scientists study the genetic basis of disease, susceptibility and resistance etc.

Negative models:

Negative models Some animals are resistant to a particular condition or disease. Examining why this is the case may provide answers to questions about disease resistance and its physiological basis.

ORPHAN MODELS:

ORPHAN MODELS Orphan models are conditions appearing naturally in an animal, for which there is no known human counterpart. Historically scrapie in sheep was such a model, but now is useful as a model for the human spongiform encephalopathies that are of so much concern (eg., "mad cow disease" and CWD, chronic Wasting Disease in deer).

THANK YOU:

THANK YOU .

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