experiment of pharmacology describing the principle and procedure of analgesic activity of drug using eddy's hot plate method

2. AIM:
TO STUDY ANALGESIC ACTIVITY OF DRUG USING EDDY’S HOT
PLATE ANALGESIOMETER IN MICE
REFERENCE
HANDBOOK OF EXPERIMENTAL PHARMACOLOGY BY
S.K.KULKARNI,3rd EDITION, REPRINT 2007, VALLABH
PRAKASHAN
REQUIREMENTS
INSTRUMENT- EDDY’S HOT PLATE
DRUGS- MORPHINE SULPHATE
APPARATUS- SYRINGE,BEAKER,ETC
ROUTE-SUBCUTANEOUS

3. PRINCIPLE
In this method heat is used as a source of pain.
Animals are individually placed on a hot plate maintained at
constant temperature(55ºc) and the reaction of animal such as
hind paw licking or jump response is taken as the end point.
Analgesic increases the reaction time
This method was described by Eddy and Leimbach in 1953

4. PROCEDURE
 Weigh and number the mice
 Take the basal reaction time by observing hind paw
licking or jump response(whichever appeals first) in
animals when placed on the hot plate maintained at
constant temperature(55ºc). Normally animals show such
response in 6-8sec. A cut off period of 15sec is observed
to avoid damage to paws.
 Inject morphine to animals and note the reaction time of
animals on the hot plate at 15,30, 60 and 120 min after the
drug administration. As the reaction time increases with
morphine, 15sec is taken as maximum analgesia and the
animals are removed from the hot plate
 Calculate % increase in reaction time(as index of
analgesia) at each time innterval.

5. OBSERVATION
BASAL
REACTION
(PAWLINK)
TIME(SEC)
JUMP
AFTER DRUG
PAWLINK
AFTER DRUG
JUMP

6. RESULT
The analgesic effect of morphine on mice was studied by
using hot plate method