Increased Sodium-Lithium Countertransport in Red Cells of Patients with Essential Hypertension

TLDR

The sodium–lithium countertransport system in red cells accepts only sodium or lithium and is not inhibited by ouabain. The study investigates whether sodium–lithium countertransport is faster in essential hypertension patients and explores its heritability as a potential link to the disease. The maximum rate of sodium–lithium countertransport was significantly higher in essential hypertension patients (0.55 mmol l⁻¹ h⁻¹) than in controls (0.24 mmol l⁻¹ h⁻¹), with first‑degree relatives showing similar elevated rates, while secondary hypertension patients had normal rates. Published in N Engl J Med.

Abstract

This paper describes experiments showing that one of the pathways of sodium transport across the red-cell membrane, sodium–lithium countertransport, is faster in patients with essential hypertension than in control subjects. This transport system accepts only sodium or lithium and is not inhibited by ouabain. The maximum rate of transport shows inherited differences. The mean maximum rate of sodium–lithium countertransport was found to be 0.55±0.02 (mean ±S.E.M.) mmol (liter of red cells x hour)-1 in a group of 36 patients with essential hypertension and 0.24±0.02 in 26 control subjects (P<0.001). The first-degree relatives of eight patients with essential hypertension and 10 control subjects had mean maximum rates of sodium–lithium countertransport of 0.54±0.05 and 0.23±0.02, respectively. Five patients with secondary hypertension had normal mean maximum rates of sodium–lithium countertransport. The relation between heritability of red-cell sodium–lithium countertransport and essential hypertension should be investigated further. (N Engl J Med. 1980; 302:772–6.)