Responses of isolated perfused arteries to catecholamines and nerve stimulation

Abstract

An isolated preparation of the dog's mesenteric artery with branching small resistance vessels and sympathetic nerves attached has been devised. The branching arterial segments were perfused by a constant-flow technique; the pressor responses to intra-arterially injected catecholamine and to nerve stimulation were recorded. The preparation gave reproducible pressor responses to injected catecholamine and to nerve stimulation for periods of several hours. Decreasing the temperature or increasing the pH (by decreasing CO2 in the gas mixture) of the vessel bath increased arterial smooth muscle tone and potentiated the pressor responses to injected catecholamine and to nerve stimulation. Increasing the temperature of the bath decreased the tone and reactivity of this preparation. Low-frequency continuous nerve stimulation potentiated the responses of this preparation to intra-arterially injected catecholamines.