EFFECTS OF GS-386, A NOVEL DIHYDROISOQUINOLINE COMPOUND, ON RABBIT ATRIAL MYOCYTES AND RAT AORTA

The effects of GS 386, a novel benzylisoquinoline derivative, on Ca2current and vasodilatation were investigated using the single rabbit a trial myocyte and rat thoracic aorta preparations. In rabbit myocytes, the Ca2+ current was recorded during various depolarizations for 200 ms from a holding potential of -40 mV using the whole patch-clamp tech nique. Superfusion of GS 386 led to a reduction of the Ca2+ current am plitude concentration-dependently, in which the IC50 value was 0.25 mu M. However, the dependence of the Ca2+ current on the membrane potent ial was not altered by CS 386. In rat aorta, CS 386 inhibited high K+- induced contractions more strongly than that induced by phenylephrine. These results indicate that GS 386 has Ca2+ antagonistic actions in r at aorta and rabbit heart. (C) 1994 Wiley-Liss, Inc.