RECEPTORS OF BIOGENIC-AMINES IN MUSCLE MEMBRANES OF MOLLUSKS

In a number of molluscs belonging to different groups, serotonin and b eta-adrenergic agonists have a stimulatory effect on the sarcolemmal a denylyl cyclase (AC) activity, which is potentiated by guanine nucleot ides. Catecholamines (isoprotenerol > adrenaline > noradrenaline) inhi bit AC activity in Anodonta cygnea sarcolemma. In muscle membranes of Anodonta, Mizuhopectin and Spisula, a serotonin receptor (5-HTR) and a beta-adrenoreceptor (beta-AR) were identified. Guanine nucleotides lo wered the affinities of 5-HTR and beta-AR to agonists.