@entity859 was shown to inhibit @entity1063 (NE) release from sympathetic nerve endings. The purpose of this study was to examine whether endogenous @entity859 restrains NE and @entity1425 release from the adrenal medulla. The effects of an @entity859 receptor antagonist, @entity28706 ( @entity28706 ), on @entity1425 and NE release induced by intravenous administration of insulin in conscious @entity35 were examined. Plasma @entity2661 were measured by HPLC with an electrochemical detector. @entity28706 significantly increased plasma @entity2922 in both control @entity35 and @entity35 treated with insulin. The effect of @entity28706 on plasma @entity2922 was significantly greater in @entity35 treated with insulin. Additional experiments were performed in adrenalectomized @entity35 to investigate the contribution of the adrenal medulla to the effect of @entity28706 on plasma @entity2922 . The effect of @entity28706 and insulin on @entity1425 in adrenalectomized @entity35 was significantly reduced compared with that of the controls. Finally, we tested whether endogenous @entity859 restrains @entity2922 secretion partially through inhibiting the renin-angiotensin system. The effect of @entity28706 on plasma @entity2922 in @entity35 pretreated with @entity3371 (an angiotensin-converting enzyme inhibitor) was reduced. These results demonstrate that under basal physiological conditions, endogenous @entity859 tonically inhibits @entity2922 secretion from the adrenal medulla, and this effect is augmented when the sympathetic system is stimulated. The effect of endogenous @entity859 on @entity2922 secretion from the adrenal medulla is achieved partially through the inhibitory effect of @entity859 on the renin-angiotensin system.

Modulation of @entity2922 release by endogenous @entity859 in the XXXX adrenal medulla.

@entity28706 :: ('MESH:C053896', 'Chemical') :: ['1,3-dipropyl-8-(p-sulfophenyl) xanthine', 'DPSPX'] @entity859 :: ('MESH:D000241', 'Chemical') :: ['Adenosine', 'adenosine'] @entity1425 :: ('MESH:D004837', 'Chemical') :: ['epinephrine'] @entity3371 :: ('CHEBI:3380', 'Chemical') :: ['captopril'] @entity2922 :: ('CHEBI:33567', 'Chemical') :: ['catecholamine'] @entity35 :: ('10116', 'Species') :: ['rats'] @entity2661 :: ('MESH:D002395', 'Chemical') :: ['catecholamines'] @entity1063 :: ('MESH:D009638', 'Chemical') :: ['norepinephrine']
@entity35 :: (10116,Species) :: ['rat']
