Humoral responses of smooth muscle from rabbit subarachnoid artery compared to kidney, mesentery, lung, heart, and skin vascular smooth muscle.

Humoral Responses of Smooth Muscle from Rabbit Subarachnoid A rtery Compared to Kidney, Mesentery, Lung, Heart, and Skin Vascular Smooth Muscle • Smooth muscle strips from rabbit subarachnoid arteries did not respond to catecholamines in concentrations which caused strips from skin, mesentery, and kidney vessels to contract. The strips from subarachnoid arteries responded to serotonin, histamine, and angiotensin II but not to bradykinin, acetylcholine, methacholine, and adenosine phosphate compounds. Heart and lung vascular strips did not respond to catecholamines but responded to acetylcholine; cardiac strips responded to dilute methacholine. Lung strips often failed to respond to histamine in usual concentrations and did respond to bradykinin. The subarachnoid strips had a distinctive pattern of response as compared to vascular tissue from other organs. Results of other isolated vessel studies are reviewed along with pertinent investigations of cerebral autoregulation, vasospasm, and autonomic nerves. The possible significance of these findings is discussed. Additional