Analgesic Effect of Diclofenac Sodium Experiment

Study Notes

Experimental Purposes:
- Observe writhing induced by acetic acid.
- Observe analgesic effect of Diclofenac Sodium in mice.

Pain Models: Physical or chemical stimulation can induce pain.
Acetic Acid-Induced Writhing: Intraperitoneal injection of acetic acid induces abdominal pain (writhing) in mice, characterized by abdomen constriction, trunk twisting, and hind limb extension.
NSAIDs and Analgesia: Nonsteroidal anti-inflammatory drugs (NSAIDs), like Diclofenac Sodium, reduce pain and writhing by inhibiting the production of prostaglandins.

Grouping: Divide the mice into two groups (control and test group), with 2 mice per group.
Weighing and Marking: Weigh mice and mark them.
Drug Injection: Administer saline to the control group and Diclofenac Sodium to the test group, dose adjusted according to mouse weight.
Acetic Acid Injection: 20 minutes after the drug injection, administer 0.5ml of 0.6% acetic acid per mouse intraperitoneally.
Observation and Recording: Observe and record the number of writhing mice in each group within 15 minutes after acetic acid injection.

Table 1: Data summarizing the number of writhing mice in the control and test groups will reveal the analgesic effect of Diclofenac Sodium. Percentage of analgesic effect is calculated as (b-B)/A x 100%, where b & B are non-writhing mice from the test and control groups respectively, and A is number of writhing mice in control group.

Acetic Acid Preparation: Acetic acid solution must be freshly prepared before each use and stored covered to prevent evaporation.
Mice Selection: Choose mice with appropriate weight (20-24g) for accurate observation of writhing.
Temperature Control: Maintain a constant laboratory temperature (18-22°C) to minimize environmental influence on the mice's response.