Bendazol (dibazol) - derivation of benzimidazole has been widely used in medical research since the second half of the 20th century. This preparation has direct myotropic effect, it serves as anticonvulsive, immunomodulatory, antiagregate, adaptogenic, actoprotector remedy, that´s why it is used in therapy, rehabilitation, prophylaxis in practical medicine. However there is not enough information in scientific literature about toxicity of the preparation. In our previous works it was proved that bendazol can be regarded as little toxic. It was also established that safe therapeutic range of bendazol covers 2 levels (from 1,25 to 40 mg/kg), that as regarding to LD 50 forms 62-64 c.u. Toxic range of the preparation (from 160 to 640 mg/kg) corresponds to 13-15 c.u. with domination of cholinergic trophotropic effect.
The aim of our work is to investigate possible mechanism of the influence of bendazol on cholinergic structures of the central nervous system.
The experiments were carried out on 60 male-rats with the mass of 200-220 gr. The animals were kept according to the rules and the experiments were carried out keeping the rules of the International Convention on the protection of the vertebrates (Strasburg, 1986).
To ascertain availability of cholinomimetic ingredient in mechanism of bendazol´s activity, we investigated its influences on M- и Н-cholinoreceptive structures and its ability to change the duration of nicotine tremor and arecoline hyperkinesis that is caused by administration of the typical cholinomimetics - nicotine and arecoline. In an hour after inserting pharmacological agents, that are being used while testing, the animals got bendazol intragastrically in dozes of 5 and 160 mg/kg. The group animals used as a control one got solvent (distilled water) intragastrically in appropriate dozes.
Experiment with arecoline showed that preliminary inserting bendazol to the rats in dozes of 5 and 160 mg/kg prolonged the latent period of hyperkinesis if the doze is 5 mg/kg but shortened its beginning if the doze is160 mg/kg. At thе same time the duration of hyperkinesis reduced depending on the doze.
The main H- cholinergic activity of the medication was evaluated according to its influence on the nicotine tremor, convulsive activity and depression of the inspiratory center. It was established that bendazol reduces the beginning of the nicotine tremor, increases its duration twice, stimulates the inspiratory center and shows little influence on the convulsive activity if the doze is 5 mg/kg. On the contrary if the doze is 160 mg/kg, the latent period of the beginning of tremor reduces if its duration increases by 120 %, depression of the inspiratory center increases 1,4 times (p≤0,05) and doesn´t influence on the convulsive activity.
Thus, according to the results of the pharmacological analysis with the help of substances that influence just on the activity of central cholinergic systems, we can suggest that bendazol possesses H-cholinomimetic activity with the dozes 5 and 160 mg/kg and M-cholinolilitic activity with the doze 160 mg/kg.
The article is admitted to the International Scientific Conference «Present-day problems of experimental and clinical medicine», Thailand, February 20-28, 2008, came to the editorial office on 28.12.07