[The characteristics of the adrenergic reaction of the portal vein in the rat liver].

Adrenergic response to noradrenaline and specific agonists of alpha- and beta-adrenoceptors phenylephrine and isopropylnoradrenaline, as well as the effect of the alpha-adrenoceptors blockers on the functional state of beta-adrenoceptors and vice versa, were studied in the rat isolated portal vein. Functional interaction between alpha- and beta-adrenoceptors was manifested in a change of alpha-receptors when beta-receptors were blocked, and a change of reaction of beta-receptors when the alpha ones were blocked. The blockade of specific receptors seems to evoke conformational changes of cell membrane, thus modulating the affinity to the agonist of the receptors of the other type.