THE RELATION OF BLOOD PRESSURE AND CONCENTRATION IN SERUM OF POTASSIUM, CALCIUM AND MAGNESIUM

Abstract

K, Ca, and Mg salts in isotonic soln. were injected intraven. at a slow continuous rate until death in 25 dogs and 11 cats. Only minor changes in blood pressure were recorded during inj. of Ca and K until terminal cardiac failure supervened, when there was an abrupt fall to zero. An immediate fall in blood pressure appeared when Mg was injected, and continued progressively to death. Magnesium is evidently a powerful vasodilator while Ca and K are without marked effect when administered similarly. The vasodilator effect of Mg is proportional to the absolute conc. of Mg in the serum, although cardiovascular mechanisms for maintenance of blood pressure observe this relationship.