This document presents a study on the effects of the skeletal muscle relaxant diazepam using a rota-rod apparatus. Mice were given injections of diazepam and their ability to remain on a rotating rod was measured and compared to untreated mice. Treatment with diazepam significantly decreased the time mice could spend on the rotating rod, indicating that diazepam has muscle relaxing properties. The study aims to evaluate diazepam's muscle relaxation effects using a non-invasive method that observes the loss of muscle grip in animals.

1. AIM: Effects of skeletal muscle relaxants
using Rota-rod apparatus.
Presented by:
Prof. Mirza Anwar Baig
Dept of Pharmcaology
AIKTC, School of Pharmacy, New Panvel

2. REQUIREMENTS:
1. Animal – mice (20-30gm).
2. Drug: - Diazepam (4mg/kg; IP).
3. Instruments: - Rota Rod.
4. Pre-treatment time: - 30 min.
5. Make a stock solution of 0.4 mg/ml and inject 1ml/100g per body
weight of the animal.

3. Principle:
 The muscle relaxation along with the calming effect is useful to reduce
anxiety and tension.
 The loss of muscle grip is an indication of muscle relaxation.
 This effect is studied in animals using inclined planes or rota rods.
 Drugs belonging to the category of benzodiazepine have a centrally
mediated muscle relaxing property.
 The time taken by the animal to fall from rotating rods is taken as an
index of muscle relaxation.
 The rotation of the rod should be adjusted such that untreated mice can
stay on the rod for 5 min.

4. Mechanism of action of diazepam:
https://www.youtube.com/watch?v=sgQvOsDQLfU

5. Rota rod and Procedure of experiment:
1. Weigh the animals and number them.
2. Turn on rota rod and select an appropriate speed (20-25rpm)
3. Place all the animals one by one and select those animals that are capable of holding
the rod in absence of drugs for 3-5 min.
4. Inject Diazepam to all the animals.
5. Note down the full time when the mouse falls from the rotating rod. Untreated mice
generally fall within 3-5 min. After 30 min of treatment with diazepam repeat the
experiment.
6. Note the onset of action and recovery from drug effect and calculate ED50.
https://www.youtube.com/watch?v=HuFBaOGBpH0
https://www.youtube.com/watch?v=v56MtrmWAs0

6. Observation Table:
Sr. No BW (g)
Dose to be
administered
(mg)
Fall time (Sec)
% decrease in Fall
time
A-B x100
A
Basel (A) Treatment (B)
1 25 0.1 66 5 92.42
2 30 0.12 60 8 86.66
3 32 0.128 61 6 90.16
4 35 0.14 62 5 91.33
5 33 0.132 63 8 87.3
Dose of diazepam: 4mg/kg

7. Result:
Treatment of diazepam to mice decreases the time spend
on rota-rod, hence it may have muscle relaxant property.

8. Applications

9. References:
• Ghosh MN. Fundamentals of Experimental
Pharmacology. Hilton & Company, Kolkata.
• Kulkarni SK. Handbook of experimental
pharmacology. VallabhPrakashan

10. Thank You