Expt 12 Anticonvulsant effect of drugs by MES and PTZ method

For educational purpose only

1. AIM: Anticonvulsant effect of drugs by MES and PTZ method. Presented by: Prof. Mirza Anwar Baig Dept of Pharmcaology AIKTC, School of Pharmacy, New Panvel

2. REQUIREMENTS: Animal – Albino rat (150-200gm) or mice (25-30gm). Drug: - Normal saline Diphenyl hydantoin - Na (50mg/ml). Instruments: - Electro- convulsometer , ear dip or corneal elect rat. Pre-treatment time: - 60 mins .

3. PRINCIPLE: The two commonly used models for convulsions are:- 1) Electrical induced. 2) Chemically induced seizures. The ability of a drug to avoid specific stages is taken as its index of anticonvulsant activity. Different types of epilepsy such as grandmal , petitmal and psychomotor type can be studied in the lab animals. Maximum electroshock (MES) induced convulsions in animals represent grandmal epilepsy . Chemo convulsion due to pentylene tetrazole produces tonic type of convulsion resemble petitmal convulsion in human

4. PRINCIPLE: contd … In MES convulsion the electroshock is applied through corneal electrodes or ear dips. When corneal electrodes are applied and optic stimulation is given cortical excitation is produced and typical convulsions can be divided in 6 parts Such as:- Latent period Clonus Tonic Flexion Tonic Extension Clonic Convulsion Depression / Stupor The duration of each phase varies, the current tonic extension of hind limbs is regarded as the most intense component of a convulsion

5. PROCEDURES : Mice of either sex weighting about 25-30 gm are used for the experiment. One day before testing , the animals are given with an electrical shock of 150 mA for 0.2 seconds. It produces extension of hind limbs . Those animals which produce positive results are selected. The selected animals are divided into 2 groups of 6 animals. One group receives the test drug while the other receives saline or vehicle. Shock is given to all animals after 1 hours of drug administration and the time taken by each phase of convulsion is noted.

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

7. Thank You