Increased Endothelin-1 Mrna Expression in Peripheral Blood Monocytes of Dialysis Patients

Abstract

To compare plasma endothelin (ET)-1 level and ET-1 mRNA level in peripheral blood monocytes of patients undergoing hemodialysis (HD) or continuous ambulatory peritoneal dialysis (CAPD). Endothelin-1 mRNA level in peripheral blood monocytes and plasma ET-1 level were studied in 30 HD patients, 15 CAPD patients, 20 chronic renal failure patients not being dialyzed, and 20 normal healthy controls. Hemodialysis patients were dialyzed three times per week with a bicarbonate dialysate. Different types of dialyzer membrane, viz., cellulose triacetate, cuprophane, polysulfone, polyacrylonitrile, and ethylenevinylalcohol were used in 8, 6, 6, 5, and 5 patients, respectively. Continuous ambulatory peritoneal dialysis patients were dialyzed with four daily exchanges of a 2-L dialysate containing glucose at a concentration of 1.5% to 2.5%. Higher levels of ET-1 mRNA in monocytes were observed in HD patients than in CAPD patients (p < 0.01), chronic renal failure patients (p < 0.01), or normal healthy controls (p < 0.001). The level of ET-1 mRNA in monocytes at the end of HD was not significantly higher than that at the start of HD. In addition, these mRNA levels in HD patients showed little difference with different types of dialysis membrane. Plasma ET-1 level in HD patients (10.2 +/- 2.4 pg/mL) was also higher than that in CAPD patients (7.8 +/- 1.6 pg/mL, p < 0.01), in chronic renal failure patients (4.8 +/- 1.2 pg/mL, p < 0.01), or in normal controls (2.6 +/- 0.8 pg/mL, p < 0.001). Dialysis itself did not significantly affect ET-1 mRNA levels in monocytes. Chronic stimulation of peripheral blood monocytes may be associated with higher levels of ET-1 mRNA and plasma ET-1 in HD patients than in CAPD patients.