In order to evaluate the role of renin-angiotensin system and sympathetic nerve system to maitain the blood pressure during regular hemodialysis (HD), we examined the level of plasma renin activity (PRA), plasma norepinephrine (PNE) and plasma epinephrine (PE) before and after regular HD in 17 patients. The cardiac performance of them was also examined before and after HD by echocardiographic examination. 10 patients (group 1) exhibited stable blood perssure during HD, while 7 patients (group 2) exhibited a fall (≥10 mmHg) in blood pressure during HD. PNE significantly increased after HD in group 1 (217±119 to 317±141 pg/ml, mean±SD, p<0.01), unchanged in group 2 (443±387 to 538±391 pg/ml). PE did not change after HD in both groups: 25.6±17.7 to 25.6±19.8 pg/ml in group 1, 39.7±33. 5 to 34.9 ±24.1 pg/ml in group 2, PRA significantly increased after HD in both groups : 4.01±2.95 to 7.43±4.95 ngAI/ml/hr in group 1, 5.13±6.76 to 8.33±8.97 ngAI/ml/hr in group 2, p<0, 05, for each. There was not significant difference between both groups in the changes of cardiac performance before and after HD. These data suggest that sympathetic nerve system may play a important role on the maintenance of blood pressure during HD.
