Investigations on the Na⁺, K⁺-pump in Erythrocytes of Patients with Renal Hypertension

1. The ouabain-sensitive ⁴²K⁺ flux from an artificial medium into erythrocytes was measured in 29 control subjects, 66 patients with chronic parenchymatous renal disease and in 32 subjects with primary hypertension.

2. The ouabain-sensitive ⁴²K⁺ influx was reduced in subjects with chronic renal disease by about 20%, even when they were normotensive. The reduction in these patients was greater than that in patients with essential hypertension.

3. The changes in ⁴²K⁺ influx and Na⁺ content with a decrease in the ⁴²K⁺ influx/Na⁺ content ratio suggest an inhibition of the Na⁺ pump in the patients with chronic renal disease.

4. The inhibition of the Na⁺ pump may be secondary to the hypervolaemia which we suggest is the initial event leading to renal hypertension.