Dopamine inhibits prostaglandin F2 alpha-induced depolarization of rabbit jejunal arteries via activation of DA1-receptors.

In rabbit jejunal arteries, the membrane potential of single smooth muscle cells decreased on the application of noradrenaline 3 mumol/l. LY 171555 1 mumol/l did not change, whereas SKF 38393 10 mumol/l reversed the effect of noradrenaline. When prostaglandin F2 alpha (PGF2 alpha) was used to evoke depolarization in the presence of prazosin 0.1 mumol/l, rauwolscine 1 mumol/l and propranolol 1 mumol/l, both SKF 38393 10 mumol/l and dopamine 10 mumol/l repolarized the membrane. SCH 23390 1 mumol/l antagonized the effects of SKF 38393 10 mumol/l and dopamine 10 mumol/l. Thus, the change in membrane potential is mediated by a DA1-receptor.