The action of sodium and potassium on blood vessels and its relation to hypertension

Summary

1. The reaction of blood vessels to sodium and potassium ions have been studied: (a) by perfusing the hind limbs of the dog with isotonic solutions of sodium and potassium chlorides; (b) by direct microscopic observation of the blood vessels in the mesentery of the guinea pig and dog; (c) by studying the reaction of rings from dog’s aorta.

2. The effect of the above ions on the contractile mechanism of the smooth muscle of the arterioles was studied by the dying muscle technique and by prior heating to 50°C.

3. Sodium has a contractile and potassium, a relaxing effect on the contractile mechanism of the smooth muscle of the arterioles. This explains the role of sodium in essential hypertension.