Effects of magnesium on isolated canine coronary arterial tension

Abstract

The effects of magnesium on the tension of isolated canine coronary arterial strips were studied.

In the solution containing K⁺ of 20 mEq·l ⁻¹, Ca²⁺ of 4 mEq·l ⁻¹, and Na⁺ of 127 mEq·l ⁻¹, the tension was 811±111 mg with Mg²⁺ of 1 mEq·l ⁻¹, 494±135 mg with Mg²⁺ of 10 mEq·l ⁻¹, 272±126 mg with Mg²⁺ of 20 mEq·l ⁻¹, −52±63 mg with Mg²⁺ of 30 mEq·l ⁻¹, −69 ±80 mg with Mg²⁺ of 40 mEq·l ⁻¹. In the solution containing K⁺ of 20 mEq·l ⁻¹, Na⁺ of 12 mEq·l ⁻¹ and Ca²⁺ of 0 mEq·l ⁻¹, the tension was 102±22 mg with Mg²⁺ of 1 mEq·l ⁻¹, 3±35 mg with Mg²⁺ of 10 mEq·l ⁻¹; −49±33 mg with Mg²⁺ of 20 mEq·l ⁻¹, −59±49 mg with Mg²⁺ of 30 mEq·l ⁻¹, −65±54 mg with Mg²⁺ of 40 mEq·l ⁻¹.

The data demonstrated that Mg²⁺ above 30 mEq·l ⁻¹ inhibited the increase in tension caused by Ca²⁺ and Mg²⁺ above 20 mEq·l ⁻¹ inhibited the increase in tension caused by low Na⁺ concentration.