ATP stimulated cyclic AMP formation in bovine chromaffin cells is enhancedby neuropeptide Y

ATP increases cAMP formation in bovine chromaffin cells, EC50 = 7.1 X 10(-6 ) M. NPY, EC50 = 4.1 x 10(-8) M, increases the efficacy of ATP (1.5-2 fold) . Inclusion of the selective Y1 receptor antagonist 1229U91 produced a decr ease in NPY potency (EC50 = 2.7 x 10(-7) M). PTX pretreatment did not aboli sh either the effect of ATP nor the enhancement by NPY. NPY could also enha nce the ability of angiotensin and bradykinin to increase cAMP formation. T he selective phospholipase C inhibitor, U73122, and the selective protein k inase C inhibitors, bisindoiylmaleimide I and RO-31-8425, were effective in hibitors of the enhancing effect of NPY. (C) 2001 Elsevier Science Inc. All rights reserved.