| Abstrakt: |
It was found that chloramphenicol (levomycetin) in concentrations of 0.07 to 0.14 mg/ml induced suppression of contractions of the isolated small intestine of rabbits. The mechanism of that action was studied with the use of pharmacological analysis of the changes in activity of the smooth muscle organs under the effect of chloramphenicol, as well as with the use of direct determination of catecholamines in the perfusion liquid washing the intestine. The studies with the isolated intestine, uterus and ear vessels of the rabbit ear, the isolated uterus of cats and rats before and after exposure to acetylcholine and adrenaline, atropine, prozerine, ergotamine, cocaine, urea and barium chloride showed that the adrenenergic properties of chloramphenicol played the main role in the mode of its action on the smooth muscle organs. It was demonstrated that treatment of the rabbit isolated intestine with chloramphenicol resulted in an increase in the catecholamine concentration in Tirode liquid washing the organ. The data provided a supposition that the mechanism of the suppressing action of chloramphenicol on the intestine lies in irritation of the adrenenergetic nervous fibres and liberation of catecholamines, which excite the adrenoreceptors of the intestine myoneural system resulting in inhibition of the organ contractions. |
