This document provides information on experimental pharmacology and the use of laboratory animals. It discusses several common laboratory animal species - mice, rats, guinea pigs, and rabbits - including their characteristics, housing, feeding, and experimental uses. Methods of euthanasia are also covered, outlining both chemical and physical approaches. The key points are that experimental pharmacology involves testing drugs on laboratory animals while ensuring humane treatment, and that the choice of euthanasia method depends on providing a painless and reliable death.

1. Experimental
Pharmacology

5. • Experimental pharmacology – great imp
• Experimenter should take outmost care
• Sacrificing - human
• Euthanasia – painless killing
• Laboratory animals – breaded and handled in
laboratory
•Mice
•Rat
•Guinea pig
•Rabbits

6. RAT
Species: Rattus norvegicus
• Wister starin is commonly used
• Other strains
• Wistar rat
• Sprague Dawley rat
• Bio breeding rat
• Long-Evans rat
• Zucker rat
• Hairless rats
• RCS rats
• Shaking rat Kawasaki

8. 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 pancreatomy
• Stomach, fundus and pyloric parts are clear lining between them
• Gastric acid secretion is continuous

15. EXPERIMENTAL USE
• psychopharmacological studies
• Study of analgesics and anticonvulsants
• Bioassay of various hormones, such as insulin, oxytocin,
vasopressin
• Study of oestrus cycle, mating behaviour and lactation
• Isolated tissue Pre's
• Chronic study
• Gastric acid secretion
• Hepatotoxicity studies
• Study on mast cells

16. 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

17. • Normal temperature:- 37.4
• Pulse rate:- 120
• Oestrous cycle:- 4-5 days
• Gestation period:- 19-21 days
• Weaning age:- 19-21 days
• Mating age:- 6-8 weeks
• Litters:- 8-12 yearly; average litter, 7-8
• Room temp.:- 20-21
• Humidity:- 50-60 %
• Weight- weaning : 7g ,adult:- 25-28 g

18. Cage(Mouse)
• Many different designs of mouse and no one
pattern is the standard
• Aluminium box approx. 6X12X6 in deep with
tapering side to facilitate stacking .
• The lids are made of steel sheet or of strong wire
mesh and are designed so that hopper is built into
them and accommodation provided to hold the
drinking bottle.
• The cages are light, durable and easily sterilized by
dry or moist heat.

19. Feeding(Mouse)
• Pelleted diets such as diet 86 of Howie(1952) or
diet 41 of Bruce (1950) are satisfactory
• Fresh water in drinking bottles must be provided

22. Handling(Mouse)
• An assistant takes a grip on the middle of tail of the animal
with the left hand and gently raises the hind limbs floor of
the cage
• A mouse held in the position cannot turn around the bite.
• Then with the right finger and thumb a fold of skin is taken
up as close as possible to the head.
• The animal can now be lifted into convenient position for
the operator to carry out simple inoculation procedures.
• Place the animal on a rough surface and hold it by its tail
with right hand, then pick up loose skin at the base of neck
with the left forefinger and thumb, lift and turn the left
hand palm uppermost at the same time catching the tail and
pressing it against the palm with the left little finger.
• The right hand is free to pick up the syringe

43. GUINEA PIGS ( CAVIA PORCELLUS )
• Docile animals
• Highly susceptible to TB and anaphylaxis
• Highly sensitive to histamine, penicillin
• Required exogenous vit c in diet

44. • Rectal temp.:- 37.6-38.9
• Normal respiration rate:- 80 per minute
• Pulse rate:- 150 per minute
• Gestation period:- 59-72 days( avg. 63 days)
• Weaning age:- 14-21 days
• Mating age:- 12-30 weeks
• Litters:- 3 yearly ;average litter,3
• Room temp:- 18.5- 21
• Humidity:- 45%
• Weight –weaning :- 120g, adult:- 200-1000g

45. Cage (Guinea pig)
• Stock runs should be abt. 4Å~6 ft. and 1 ft. 8 in high
• One square foot of space should be allowed for
each animal
• not more than 25 animals should not be kept in any
one pen.
• For expt. Animals galvanized iron cages are
recommended and sterilized.
• A convenient size of 14X9X8 in fitting in a tray 1.5 in
deep

46. Feeding(Guinea pig)
• A diet in pelleted form is recommended in
preference to mashes.
• Diet of Bruce and Parks (1947) contains balanced
proportions of protein, fats and carbohydrate with
added vitamins salt and trace element.
• Crushed oats 2 part+ Broken bran 1 part
• Supplemented with cabbage and hay
• Necessary to add fish or meat meal.

47. Handling
• Place one hand across the back of the animal with
thumb behind the shoulder and the other fingers
well forward on the opposite side
• Lift the animal gently and support its weight with
other hand placed palm uppermost under the hind
quarters.

51. EXPERIMENTAL USES
• Evaluation of bronchodilators
• Anaphylactic and immunological studies
• Study of histamine and antihistamines
• Bioassay of digitalis
• Evaluation of local anaesthetics
• Hearing experiments because of sensitive cochlea
• Isolated tissues especially ileum, heart
• Study on TB and ascorbic acid metabolism

52. RABBITS (Lupas cuniculus)
• Docile animal
• New Zealand white strains are widely used
• It has huge caecum and long appendix
• Enzyme atropine esterase is present in rabbit liver
and plasma so it can tolerate large
• Doses of belladonna (atropine)

53. • Rectal temperature:- 38.7 C-39.1 C
• Normal respiratory rate:- 55 per minute
• Pulse rate:- 135 per min
• Gestation period:- 28-31 days
• Weaning age:- 6-8 weeks
• Mating age:- 6-9 months
• Litters:- 4 yearly ; average 4 litter
• Room temp:- 15.5-18.5
• Humidity:- 40 -45 percent
• Weight – adult:- 0.9-6.75 kg

54. Cage
• Cages are best made of
galvanized iron.
• The minimum size for a
medium sized rabbit is
2X2X1(1/2)ft.,
• Young rabbits up to 3 months
of age may be housed together
but after that time sex should
be separated.
• From 8 -10 young rabbits may
be kept together in pen similar
to that used for guinea pigs.

55. Feeding(Rabbit)
• Pelleted diet 18 of Bruce and Parkers(1947) or
commercial breeders pellets are suitable
• Daily supply of 2.5 0z(72 gm) of a mixture of one
part oats and three parts bran may be fed as a
slightly moist mash
• Green stuffs or root vegetables
• Clean drinking water

56. Handling(Rabbit)
• Smooth ear of the rabbit back
• pick up the ears and loose skin at the back of the
neck with one hand in a firm grip
• place the other hand under the hind quarter to
support the weight and lift gently.
• Never be lifted by ear alone
• Should be placed on a non-slippery surface
• If restraint is required during anaesthesia or
inoculation , should be wrapped in a roller towel or
placed in a special box.

60. EXPERIMENTAL USES
• Pyrogen testing
• Bioassay of anti-diabetic, curariform 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 anaesthetics
• Study on meiotic and mydriatics

61. FROGS (RANA TIGRINA)
• Most commonly used in physiology, pharmacology
and toxicology
• Used before 200 years
• Amphibian animal safe to handle
• Cannot breed in lab

62. EXPERIMENTAL USES
• Isolated preparations, heart, rectus abdominis
muscle
• Drugs acting on CNS
• Drugs acting on NMJ

67. Euthanasia

68. • Reliability and irreversibility
• Minimum pain, distress, anxiety or apprehension
• Minimum delay until unconsciousness
• Safety and emotional effect on personnel
• Compatibility with requirement and purpose, including
subsequent use of tissue and
• • Compatibility with species, age and health status
• Euthanasia methods are broadly classified as;
• Chemical methods (Inhalants/Non-inhalants)
• Physical methods.

69. Inhalant Anesthetics
• Halothane
• Enflurane
• Sevoflurane
• Methoxyflurane
• Isoflurane
• Desflurane
are preferred for euthanasia in animals.

70. CO2
• Carbon dioxide is an effective and widely used
agent to euthanize rodents due to rapid hypoxia
which further leads to depression of vital centers.
(Maintain 20% -70% of the chamber volume per
minute).
• This method is preferred in several animal but it is
dangerous to use, so precaution should be taken
while using it

71. Nitrous oxide
• N2O is not preferred due to lack in fast onset
of anesthesia, but may produce hypoxemia
and cardiac or respiratory arrest.
• However, it may be used in combination with
other anesthetics to speed anesthesia onset.

72. Ether
• Ether was formerly used extensively, but is now
only acceptable conditionally.
• The reason is being irritant to mucous membranes
and risk of fire and explosion.
• The use of ether is prohibited in many countries.

73. Non-inhalant Anesthetics
• Barbiturates:
• Sodium pentobarbital is the most rapid and
reliable method of euthanasia for most
experimental animals.
• In non-rodent species, barbiturates are given
intravenously to be most effective.
• Intraperitoneal injection of barbiturates is
acceptable for euthanasia in small mammals.

74. Potassium chloride (KCl)
• KCl induces immediate cardiac arrest without
any significant depression of the central
nervous system.
• Hence, it must only be used after the animal
is deeply anesthetized

75. Magnesium sulphate (MgSO4)
• MgSO4 produces its action through cardiac
arrhythmia, neuromuscular blockade and
deep anesthesia, hence ultimately animal
gets euthanized due to cardiac arrest and
neuromuscular blockade.

76. Neuromuscular Blocking Agents
(Succinycholine, Curare, etc.)
• These agents induce muscular paralysis and
death because of suffocation.
• Distress onset is more, hence less preferred
for euthanasia.

77. Physical Methods
• Physical methods are performed by skilled
and experienced personnel with appropriate,
well maintained equipment.

78. • Cervical dislocation: Humane technique for
euthanasia which is frequently used for
mice, rats, guinea pig, rabbits (weighing less
than 1 kg) and other rodents.
• Decapitation: Decapitation may be used to
euthanize rodents and small rabbits. Except
in neonatal animals, a guillotine is generally
used.

79. Microwave irradiation
• Special instruments designed (appropriate power
and microwave distribution) for this purpose, which
is used when an experiment requires fixation of
mouse or rat brain metabolites in vivo without
losing anatomic integrity of the brain.

80. Penetrating captive bolt
• This method is conditionally acceptable and made
for ruminants, horses, and swine when chemical
agents are scientifically contraindicated.
• This method is not employed in the laboratory
animals.

81. Euthanasia of Poikilothermic
(Cold-blooded) Animals
• The euthanasia of poikilothermic animals is
different due to differences in the pharmacokinetic,
respiration and tolerance to cerebral hypoxia
between these species and homeothermic animals.
• Chemical agents:
• Pentobarbital,
• Tricainemethane sulfonate or
• benzocaine HCl.

82. • Intraperitoneal administration of pentobarbital is
an effective method of euthanasia in amphibians.
• Tricaine methane sulfonate or benzocaine
hydrochloride may be placed in the water of
amphibians and fish to produce anesthesia and
prolonged contact may produce death.
• Inhalant anaesthetics may be used for amphibians
and reptiles but due to the low oxygen
requirements for amphibian, the onset of
unconsciousness and death will be significantly
lengthened.

83. Physical methods
• Poikilotherms may be euthanized by stunning
followed by decapitation or pithing to ensure
death.
• In frogs and toads, pithing the brain (single pithing)
and spinal cord (double pithing) are effective and
acceptable methods.