INFLUENCE COLCHICINE ON CONTRACTILE REACTIONS OF PULMONARY ARTERY: PP.31.232

Abstract

The purpose of this work was to investigate role of microfilament and microtubul for regulation of contractile reactions using guinea pig arterial vascular smooth muscle. Contractile reactions of isolated segments of pulmonary artery have been investigated by means of a mehanografic method. For modulation of cytoskeleton is used colchicine (10 mkM, time of influence 90 min). The amplitude of contractile responses of smooth muscle segments was calculated as a percentage of the amplitude of the control hyperpotassium reduction (40 mM). In the first series of experiments investigated the influence of the disintegration of the cytoskeleton by colchicine pre-treatment on hyperpotassium reduction. Found that all the segments meet the reduction of such impacts, but in some segments of the observed decrease in the amplitude reduction of 15.7 ± 6.3%, in another part of the reduction in segment increased by 36.4 ± 4.3% compared with control. In the second series of experiments was to study the participation of the cytoskeleton in contractile responses of segments of pulmonary arteries, developing in response to the addition of phenylephrine (0.01 mM). The magnitude of the contractile response to the action of substance to pre-treatment with colchicine was taken as 100%. After pre-treatment with colchicine to reduce the amplitude of phenylephrine decreased to 41.7 ± 15.7%. Thus the participation of the cytoskeleton in the regulation of the contractile response may depend on the nature of the current factor, in one case, it potentiates the reduction in the other - weakens it.