Nature of [3h]rilmenidine binding to membranes of rat cerebral cortex

Abstract

The binding of [3H]rilmenidine to membranes of rat cerebral cortex was studied in order to ascertain which receptor populations this novel antihypertensive interacts with in the cortex. A catecholamine-sensitive, a2-adrenoceptor binding site was identified which represented up to 50% of specific, 2 nmol/L [3H]rilmenidine binding and was displaceable by the catecholamines in the rank order epinephrine —b norepinephrine —» dopamine —» isoproterenol. Some imidazolines such as clonidine, naphazoline, and idazoxan and the guanidino compound guanabenz completely and potently inhibited [3H]rilmenidine binding from both catecholamine-sensitive and -insensitive sites. The substituted imidazole and gu..