Action of Angiotensin on Sympathetic Nerve Endings in Isolated Blood Vessels

Abstract

THE recent experimental findings^1,2 of a diminished effect of administered angiotensin on blood pressure after acute sympathectomy or pretreatment with reserpine have directed attention to a possible relationship between the effects of angiotensin and the sympathetic nerve system. In dogs, McCubbin and Page³ described an effect of angiotensin on the sympathetic nervous system resulting in an enhanced response to agents and procedures which cause release of endogenous noradrenaline. Later, Lewis⁴ observed an angiotensin-induced release of catecholaminas from the suprarenal medulla of cats. In connexion with this finding he tentatively discussed an action of angiotensin at the vascular wall by local liberation of catecholamines from the sympathetic nerve endings. The two kinds of experiments (a and b) presented here were undertaken to obtain further information on the relationship between angiotensin and the sympathetic vasomotor action.