EFFECT OF MAINTENANCE HEMODIALYSIS ON PLASMA ENDOTHELIN IN CHRONIC RENAL FAILURE
1993 Volume 43 Issue 2 Pages 123-131
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1993 Volume 43 Issue 2 Pages 123-131
Fourteen patients with uremia (10 men, 4 women), undergoing hemodialysis (HD) three times a week, were studied. Endothelin (ET) concentrations were measured by radioimmunoassay. The plasma immunoreactive-endothelin (ir-ET) concentrations were found to be markedly higher in the uremic patients before HD than in normal controls or in essential hypertensive patients with normal renal function. After HD, the plasma levels of ir-ET significantly decreased, though not in association with a reduction in blood pressure.
The blood samples and aliquots of dialysate were obtained at the beginning and the end of HD from 6 patients. Since the antisera (Amersham, U.K.) used had cross reactivity with ET1, ET-2 and big ET-1, both the plasma and dialysate samples were analyzed by HPLC. Both ET1 and big ET-1 levels in plasma were significantly decreased by one course of HD, but the ratio of ET-1 to big ET-1 was unchanged. In dialysate, ET-1 was detectable at the beginning and the end of HD, but big ET-1 was beneath the detection limit, which suggested that ET-1 was converted from big ET-1 in the systemic circulation.
Moreover, the changes in uremic plasma levels of ir-ET or ET-1 did not correlate with changes in the mean blood pressure on a single chronic HD, indicating that circulating ET-1 in blood is not involved directly in the maintenance of blood pressure in uremic patients undergoing HD.
