INCREASED ENDOTHELIN-1 MESSENGER-RNA EXPRESSION IN PERIPHERAL-BLOOD MONOCYTES OF DIALYSIS PATIENTS

Objective: To compare plasma endothelin (ET)-1 level and ET-1 mRNA lev el in peripheral blood monocytes of patients undergoing hemodialysis ( HD) or continuous ambulatory peritoneal dialysis (CAPD). Design: Endot helin-l mRNA level in peripheral blood monocytes and plasma ET-I level were studied in 30 MB patients, 15 CAPD patients, 20 chronic renal fa ilure patients not being dialyzed, and 20 normal healthy controls. Hem odialysis patients were dialyzed three times per week with a bicarbona te dialysate. Different types of dialyzer membrane, viz., cellulose tr iacetate, cuprophane, polysulfone, polyacrylonitrile, and ethyleneviny lalcohol were used in 8, 6, 6, 5, and 5 patients, respectively. Contin uous ambulatory peritoneal dialysis patients were dialyzed with four d aily exchanges of a 2-L dialysate containing glucose at a concentratio n of 1.5% to 2.5%. Results: Higher levels of ET-l mRNA in monocytes we re observed in HD patients than in CAPD patients (p < 0.01), chronic r enal failure patients (p < 0.01), or normal healthy controls (p < 0.00 1). The level of ET-1 mRNA in monocytes at the end of HD was not. sign ificantly higher than that at the start of I-ID. In addition, these mR NA levels in HD patients showed little difference with different types of dialysis membrane. Plasma ET-1 level in no 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). Conclusion : Dialysis itself did not significantly affect ET-1 mRNA levels In mon ocytes. Chronic stimulation of peripheral blood monocytes may be assoc iated with higher levels of ET-l mRNA and plasma ET-l in HD patients t han in CAPD patients.