Effect of Adrenal Arterial Infusion of Different Mg 2+ Concentrations on the Spontaneous Release of Catecholamines in the Anesthetized Dog 1

Abstract

Summary

The effect of magnesium ion concentration on the spontaneous release of catecholamines from the adrenal gland has been studied in anesthetized dogs under nearly physiological conditions. A very slight elevation (15-20%) of Mg²⁺ concentration in the blood supply of the adrenal gland was found to be sufficient to inhibit the spontaneous release of norepinephrine and epinephrine. Higher concentrations of Mg²⁺ (up to double the control) had still greater effects, but in this case a preferential decrease of epinephrine in the adrenal outflow resulted. A possible involvement of aldosterone in the differential release of norepinephrine and epinephrine is discussed. Plasma renin activity in peripheral blood was not affected and the effect of Mg²⁺ does not seem to be mediated through the renin-angiotensin system.