Experiment 2 Analgesic Action Of Morphine

Name: student number: Experiment 2 Analgesic action of morphine (The method of hot plate)

Aim:
To observe the analgesic effect of morphine.
Discussion:
Stimulate the position of animal by temperature to produce pain reaction. Put the mouse on the metal plate which has heat up to 55oC. The pain reaction is identified as to lick the hind paw. Pain threshold is the time of producing pain. Reflect abiritation by mensurating the pain threshold change before and after take medicine.
Materials:
1. Animals: mice(female)
2. Drugs: 0.1% morphine hydrochloride, normal saline
3. Equipment: hot plate
Methods:
1. Set the temperature at 55oC and place a mouse on the hot plate, then turn on the time switch and record the time, observe the mouse’s reaction to hot stimulation. The pain reaction is identified to lick hind paw itself, take out the mouse when it licks itself. After 5 minutes, do the same test again. The mouse can be used to do the test when its two pain reactions happen in 5-30 seconds. The average time of two normal pain response is used to normal pain reaction time before drug treatment. Each group’s choices 20 eligible mice, weigh and mark them, and giving them follow drugs.

2. Mouse are divided into two groups: control group and morphine group. Every group has ten mouse. Control group is treated with 0.1% morphine hydrochloride 0.1ml/10g
3. After treatment, all mice are determined the latent period of pain response at 10, 20, 30, 40, 50 and 60 minutes according to the method above.

Results:
Calculating the percentage of pain threshold of the mouse

Mark
Weight (grams)
Before injecting (seconds)
After injecting 10 minutes later
After injecting 30 minutes later
After injecting 50 minutes later
Normal
saline
1
30.5
23.57
7.81
17.76
6.01

2
32.5
15
13.02
5.30
4.61

3
29.5
12.58
4.01
1.39
4.00

4