[Effect of adrenoreceptor blockade and stimulation on the resistance and capacitance of intestinal vessels]

Abstract

Resistography and extracorporeal venous flow in cats revealed that i. a. administration of noradrenaline (NA) increased the intestine vascular resistance, adrenaline (A) decreased it and novodrine (N) sharply decreased it in all the experiments. After the alpha-adrenoreceptors blockade with dihydroergotoxin, NA as well as A decreased the vascular resistance whereas N exerted just the same dilator response as before blockade. Blockade of B-adrenoreceptors with obsidan augmented the NA constriction of the arterial vessels, sharply decreased their N dilatation and induced obvious constrictor responses to A. The vascular resistance after the alpha-blockade decreased by 7% whereas after the beta-blockade it increased by 26%. The venous outflow from the intestine increased after A and N disregarding the alpha-blockade but being prevented with the beta-blockade. Irregular changes of the venous outflow in response to NA preserved after the blockade of both types of adrenoreceptors.