Rodents, especially rats and mice, are widely used in drug research due to their biological similarities to humans. They are small, inexpensive to house and breed, and have short lifespans, making them practical for medical experiments. Genetically modified rodents have been particularly useful for studying diseases like Parkinson's, cancer, and cystic fibrosis. While rodents provide insights into human biology and disease, some argue against animal testing due to ethical concerns. Overall, rodents serve as important but imperfect models that have contributed greatly to medical advancements.

1. RODENTS USED IN DRUG RESEARCH
-PRESENTED BY
MADHURA NEWREKAR
M.PHARM (QUALITY ASSURANCE)
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2. OVERVIEW
 SIGNIFICANCE OF USING ANIMALS AS A RESEARCH MODEL
 RODENTS – INTRODUCTION
 SIGNIFICANCE OF RODENTS AS ANIMAL MODEL
 RODENTS-(EXPERIMENTAL USES , PHYSIOLOGICAL AND BIOLOGICAL DATA)
• RATS
• MICE
• GUINEA PIGS
• HAMSTERS
 PROS AND CONS OF USING RODENTS AS AN ANIMAL MODEL
 IMPORTANT RODENT MODELS
 CONCLUSION
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3. SIGNIFICANCE OF USING ANIMALS AS A
RESEARCH MODEL
• Their basic cell processes are the same as in humans and they perform
similar vital functions.
• Simple animals can be used to study complex biological systems such as the
nervous or immune systems ,which follow the same basic organization and
function in all animals.
• Studying disease mechanisms in animal models leads to development of new
technologies and medicines.
• Animals which are altered to create models of disease are known as induced
models.
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4. Animals used in drug
research
Mammals
Rodents
Nonrodents
Miscellaneous
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5. RODENTS - INTRODUCTION
 Rodents are mammals of the order Rodentia, which are characterized
by a single pair of unremittingly growing incisors in each of the upper
and lower jaw.
 Well known rodents are mice , rats , squirrel ,porcupines , guinea pigs
, hamsters.
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6. RODENTS
• Rodent models are widely used by researchers in the pharmaceutical
industries. 95 % of all lab animals are rodents.
• For probing the immune , endocrine , nervous , cardiovascular , skeletal , and
other complex physiological systems.
• WHY RODENTS…?
• Small , easily housed and maintained and adapt well to known surroundings .
• Reproduce quickly and have a short life span.
• Genetic ,biological and behavior characteristics closely resemble those of
humans.
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7. RATS
rattus norvegicus
• Testing of psychological drugs.
• Hepatotoxicity studies and Toxicological studies
• They are helpful in studying oestrous cycle , mating behavior , lactation.
• Study of analgesics , anticonvalsants.
• Study on mast cells , gastric acid secretion .
• Various isolated tissues uterus ,stomach ,colon are used for studying drug
actions
Drawbacks
• No vomiting centre and have diffuse pancreas. 7

8. WISTAR RAT SPRAGUE DAWLEY RAT LONG EVANS RAT
• Quiet
• Resistant to
infection
• Low incidence of
spontaneous
tumours
• Grows more
rapidly
• Increased tail to
body ratio than
wistar rats
• Multipurpose model
organism
• Frequently used in
obesity and
behavioral research.
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9. ZUCKER RATS HAIRLESS RATS BIOBREEDING RATS
• Genetically modified rats
to study obesity and
hypertension drugs.
• They are used to
study the drugs
on genetic kidney
disease and
compromised
immune system.
• They are used
as models to
study
autoimmune
type I diabetes.
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10. MICE
mus musculus
• Swiss albino mice is a widely used species.
• They have similar reproductive and nervous system to humans and suffer from
same diseases such as cancer ,diabetes and even anxiety.
• Their short life span and fast reproductive rate makes it possible to investigate
biological processes at every stage of life.
• Toxicological , teratogenecity studies also studies related to genetics and
cancer.
• Bioassay of insulin ,screening of analgesic and anticonvulsant drugs .
• Screening of chemotherapeutic agents and drug action on CNS.
• Isolated tissues are rarely used with the exception of vas deferens and ileum.
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11. DIFFERENCE BETWEEN RATS AND MICE
RATS MICE
Heavier than mice Comparatively lighter in weight
Thick and heavy tail Very thin tail
22 pair of chromosomes 20 pair of chromosomes
Longer gestation period Shorter gestation period
Average lifespan is more Shorter life span
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12. GUINEA PIGS
cavia porcellus
• They are docile in nature, very susceptible to anaphylactic shock and
tuberculosis, highly sensitive to histamine.
• Vitamin C was discovered through research on guinea pigs .
• They were also crucial to the development of vaccines of diptheria, TB .
• Evaluation of local anaesthetics.
• They are used for the evaluation of bronchodialator compounds in asthma
studies.
• They are suitable for hearing experiments also used to study isoniazid
toxicity.
• Various isolated tissue such as ileum, tracheal chain, vas deferens are used.
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13. Continued..
• They were important in the discovery and early development of beta blockers to
treat high pressure and drugs to treat stomach ulcers.
• Numerous developments have used their intestines for example anti nausea drugs
used by cancer patients and the identification of naturally pain killing substances
known as enkephalins.
• NUTRITIONAL RESEARCH :
• Along with vitamin C , guinea pigs need high levels of folic acid , thiamine , arginine
, potassium which make them useful in nutrition studies.
• They also carry most of their plasma cholesterol in low density lipoprotein , so they
are useful in the study of cholesterol and lipoprotein metabolism.
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14. PHYSIOLOGICAL DATA OF RODENTS
PARAMETER RAT MOUSE GUINEA PIG
DAILY FOOD
INTAKE(g)
10-20 4-5 40-50
HEART
RATE(BEATS/MIN)
300-500 330-780 260-400
RESPIRATORY
RATE/MIN
65-180 84-230 70-104
ARTERIAL
BP(SYSTOLIC)
116 113 77
ARTERIAL
BP(DIASTOLIC)
90 81 47
Hb(g/100ml) 12-17.5 10-19 8-15
RBC (MILLION/cmm) 7..2-9.6 4.9-12.5 8-15
WBC(MILLION/cmm) 6-12 4-12 4-11
BLOOD
VOLUME(%B.W)
6-7 7-9 6-12
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15. BIOLOGICALL DATA OF RODENTS
PARAMETER RAT MOUSE GUINEAPIG
ADULT WEIGHT(g) 250 20-40 800
AVERAGE LIFE SPAN(YEARS) 2-3 1.5-2.5 3-5
AVERAGE AGE SUITABLE FOR EXPERIMENT (MONTHS) 1.5 0.75 3
AGE OF FIRST MATING(MONTHS) 2.5-3 1.5-2 3
BREEDING HABITS(1 MALE TO NUMBER OF FEMALES) 5 3 6
GESTATION PERIOD(DAYS) 21-23 19-21 68
AVERAGE LITTER SIZE (g) 8-10 6-12 3-4
NO OF LITTERS PER YEAR 4 6 8-10
AGE AT WEANING (DAYS) 21 21 14-21
WEIGHT AT WEANING(g) 35-45 10-14 160-230
DURATION OF SEXUAL LIFE(MONTHS) 12 12 14
REST PERIOD OF FEMALES BETWEEN MATINGS(DAYS) 15 15 15
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16. GERBIL
meriones unguiculatus
• Also known as sand rats or jirds .Their size lies between that of rats
and mice
• Used as research animal in stroke , epilepsy and heart diseases.
• Useful in study of parasitic and bacterial infections
• Used in auditory studies because hearing curve is similar to that of
humans.
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17. HAMSTER
mesocricetus auratus
• Third commonly used laboratory animal
• Two species are commonly used :
• Golden or Syrian hamster
• Chinese hamster
• Syrian hamster is most commonly used for biomedical research
because of ease of availability.
• Chinese hamster is suitable for cytogenesis research.
• They are extensively used in onco virus, influenza virus studies.
• Their cheek pouches do not have lymphatic drainage so they are ideal
sites for tissue transplants.
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18. PROS AND CONS OF USING RODENTS AS
ANIMAL MODEL
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19. IMPORTANT RODENT MODELS
1. GENETICALLY ALTERED RODENTS
• Transgenic and knockout rodents have been created with revolutionary new
technology. While transgenic mice have had a foreign gene (a piece of DNA)
artificially added to their genomes, knockout mice have had a specific gene
“turned off” or made useless. A great deal of promising research relies on
these genetically altered mice. Transgenic rats also have been used in
medical Studies and found to be better models than mice for studying certain
human diseases.
• Genetically altered rodents have allowed scientists to observe what happens
during the progression of Parkinson’s disease, cancer, cystic fibrosis, heart
disease, memory loss, muscular dystrophy, and spinal cord injuries. 19

20. 2.NATURALLY OCCURRING IMMUNODEFICIENT
MICE
• SCID (severe combined immune deficiency) mice and nude (or
hairless) mice are born without thymus glands and lack functioning
immune systems.
• These mice are very Important models for studying both normal and
malignant human tissue. They also are needed to develop and
evaluate new drugs without risking Human lives.
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21. CONCLUSION
• Data from animal research are crucially important to researchers in
the pharmaceutical industry when deciding whether a potential
medicine will be effective and safe for use in humans.
• Approximately 95 percent of all laboratory animals are mice and rats.
• Easily housed and bred, short lived (2-3 years), small, and relatively
inexpensive, these rodents have become the animal model of choice
for modern medical and scientific researchers.
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22. REFERENCES
• N.V.Giridaran;The essential need for animals in biomedical research ;Rats
and mice , Foundation for biomedical research; Page no.1,2.
• Dr Larry Johnson;Pros and cons of animals in research-follow up lessen ;
Partnership for environmental education and rural health.
• Bill Yates;rodents in neuroscience research;University of
Pittsburgh;2013;pages 3-6.
• Camilla Jessel;Mice and medicine;Medical research council;2008;Pages :15-
18.
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23. THANK YOU..!!!
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