Endothelial nitric oxide synthase intron 4 polymorphism influences the progression of renal disease

Background/Aim: Nitric oxide is a potent regulator of intrarenal hemodynami cs and may influence the renal function. We investigated whether polymorphi sm of intron 4 of the endothelial constitutive nitric oxide synthase (ecNOS ) gene is related to the progression of chronic renal failure. Methods: Pol ymorphism of ecNOS intron 4 was studied in 1,005 hemodialysis patients (710 with nondiabetic nephropathy and 295 with diabetic nephropathy) and was co mpared with the findings in 189 healthy subjects. ecNOS genotypes were dete rmined by the polymerase chain reaction, followed by agarose gel electropho resis. Results: The frequencies of ecNOS4a/a, ecNOS4a/b, and ecNOS4b/b geno types were, respectively, 0% (0/189), 13.8% (26/189), and 86.2% (163/189) i n the control group; 1.7% (12/710), 22.1% (157/710), and 76.2% (541/710) in the nondiabetic nephropathy group, and 1.0% (3/295), 22.7% (67/295), and 7 6.3% (225/295) in the diabetic nephropathy group. The frequency of ecNOS4a (ecNOSa/a and ecNOSa/b) was significantly higher in both the nondiabetic gr oup and in the diabetic group than in the controls (p = 0.0025 and p = 0.04 38, respectively). Conclusion: There was a significantly higher frequency o f the a allele of intron 4 in both nondiabetic and diabetic hemodialysis pa tients, so the polymorphism of intron 4 of the ecNOS gene may have a wide i nfluence on the progression of renal disease. Copyright (C) 2001 S. Karger AG, Basel.