(3,4-Dihydroxybenzyl)-2-imidazoline (DHBI): an analogue of dopamine

(3,4-Dihydroxybenzyl)-2-imidazoline (DHBI) was prepared and evaluated for dopamine receptor activity by studying its relaxant effects in the rabbit isolated renal and ear arteries and by measuring its ability to enhance dopamine sensitive adenylate cyclase in the rat striatum. DHBI relaxed both the rabbit isolated renal and ear arteries in the presence of phenoxybenzamine (2. 9 X 10(-5)M) and propranolol (3.4 X 10(-7) M) while dopamine and the specific renal dopamine agonist 6,7-dihydroxy-2-aminotetrahydronaphthalene (6,7-ADTN) demonstrated a ratio of specificity for the renal versus the less responsive ear artery. DHBI did not cause a typical increase in adenylate cyclase activity, however DHBI did attenuate the stimulatory a