| Abstract
| - Plasma endothelin-1 (ET-1)-like immunoreactivity was measured by radioimmune assay in predialysis plasma samples from 16 chronic haemodialysis patients (7 dialysing through arteriovenous (AV) fistulae and 9 using central venous cannulae for access), from 10 patients with functioning renal transplants (5 with AV fistulae and 5 without), and from 6 healthy subjects as controls. Among dialysis patients, ET-1 was greater in those with AV fistulae than in those using cannulae for dialysis (median (range), 5.5 (3.1) pM versus 3.7 (2.0) pM, P=0.02), and in all haemodialysis patients ET-1 values were substantially greater than in normal controls (3.9 (3.2) pM versus 0.5 (0.1) pM; P=0.001). In patients with functioning AV fistulae, ET-1 concentrations obtained directly from the AV anastomosis of the fistula (4.4 (3.0) pM) were less than those taken simultaneously from the contralateral arm (5.5 (3.1) pM; P=0.04), while samples drawn from the venous side of the fistula were intermediate (4.6 (3.4) pM). In renal transplant recipients, ET-1 values did not differ significantly from those in control subjects (0.7 (1.9) pM versus 0.5 (0.1) pM, n.s.), but in these patients there was a significant difference between peripheral venous ET-1 in transplant patients with and without AV fistulae (0.8 (1.9) pM versus 0.6 (1.1) pM respectively, P=0.04). The results suggest that the increased blood flow rate through the arterialized venous circulation in the fistula arm stimulates increased ET-1 release in these patients, and that this accounts, at least in part, for the increased ET-1 found in the patients with functioning AV fistulae.
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