Sympathetic nervous function and erythrocyte cation transport systems in normotensive individuals with family history of hypertension.

Abstract

To investigate the influence of heredity to the sympathetic nervous function and the cell membrane cation transport systems, we studied the blood pressure and plasma catecholamine response to supine exercise testings by bicycle ergometer, the pressure response to noradrenaline infusion tests and the heart rate response to isoproterenol infusion tests in 88 healthy Japanese sedentary normotensive men with and without a family history of essential hypertension [FHH(+) and FHH(-)]. Several erythrocyte monovalent cation transport parameters were also measured in 74 of these individuals. In the results, (1) the systolic blood pressure response to exercise testings and noradrenaline infusion tests were larger in FHH(+) than FHH(-): (2) there was no difference between FHH(+) and FHH(-) in the heart rate response to isoproterenol infusion tests: (3) there was no significant difference between FHH(+) and FHH(-) in the increased plasma catecholamine levels to exercise testings: (4) the intraerythrocytic sodium content was significantly higher in FHH(+) than in FHH(-): and (5) several erythrocyte monovalent cation transport systems (Li-Na countertransport, Na-K cotransport and Na-K pump activity) were clearly accelerated in FHH(+). We concluded that in spite of normotension there were abnormalities of sympathetic nervous function, intracellular sodium content and several cell membrane cation transport systems in individuals with a family history of essential hypertension.