BACKGROUND
Algesia (sensitivity to pain) can be induced by various ways to the animals. Painful response can be noted with and without pain killers (analgesics). Analgesic drugs inhibit the sensitivity to pain.1 In this method, heat is the source for pain.
| Telegram | Subscribe |
| Follow | |
| Website | Click here |
Analgesic activity study
A constant heat (55 °C) will be given to the animal by hot plate and the response of the animals e.g., jumping, paw licking and withdrawal will be observed. Aim of this experiment is to study analgesic activity of drug by Eddy’s analgesiometer.
REQUIREMENTS
Animals : Mice (20-25 g) or Rat (150-180 g)
Drugs : Morphine sulphate (5 mg/kg), inject i.p. 1 ml/100 g body weight,
Other drugs: Pentazocin (20 mg/kg, i.p.), Aspirin (100 mg/kg, p.o.)
Equipment : Eddy’s hot plate (55 °C heat for painful stimulus) analgesiometer
PROCEDURE
Weigh and mark the animals. Observe the basal reaction time by placing the animals on the hot plate and note the jumping or paw licking (any of the first reaction) in animals with a constant temperature (55 °C). Usually in 6-8 sec animals show the response. A cut off period of 15 sec will be considered to avoid any damage to the paws.2
Inject drug to animals and note down the reaction period of animals on the hot plate apparatus at different time intervals including 15, 30, 60 and 120 min after the drug treatment. As the reaction time increases with drug treatment, 15 sec will be taken as maximum analgesia and the animals are to be taken from the analgesiometer to avoid injury.
Calculate percent increase in reaction time at each time interval.
Observation table.
|
S.No. |
Animal Weight |
Basal reaction time (sec) |
Reaction time after treatment | ||
|
Paw licking |
Jump response |
Paw licking |
Jump response | ||
|
1. |
|
|
|
|
|
|
2. |
|
|
|
|
|
|
3. |
|
|
|
|
|
|
4. |
|
|
|
|
|
CONCLUSION
From this experiment this can be concluded that, the drug inhibits pain stimulus and with increase in time after administration which has analgesic property.
REFERENCES
- Tripathi KD. Essentials of Medical Pharmacology. 7thedn, Jaypee brothers medical publishers (Pvt) Ltd, New Delhi; 2013.
- Ghosh MN. Fundamentals of Experimental Pharmacology. 3rd ed. Kolkata: Hilton and Company; 2005.
Also read:
- Protein denaturation by egg albumin method (in vitro)
- Analgesic activity study of drugs by hot plate (Eddy’s hot plate) method
- Study of local anesthetics by Infiltration anaesthesia in guinea pig
- Study of local anesthetics by Surface anaesthesia on the cornea of rabbits
- Study of local anesthetics by Spinal anaesthesia in rats
- Study of local anesthetics by conduction anaesthesia in frogs
- Study of biotransformation and excretion of drug
🔴 Would you like to attempt Labmonk Daily quiz? Click here
🔵 Check out Jobs & Exam Notices. Labmonk Notice Board
🔴 Labmonk Scholarships. Click here
🔵 Labmonk Blog. Click here
🔴 Do you need notes? Click here
🔵 Watch Career related videos on Youtube: Watch now !!
