Dimethylarginines in chronic renal failure

Background-Nitric oxide (NO) is a potent chemical mediator involved in many functions. In vivo production of NO is thought to be regulated by endogenous analogues of L-arginine: asymmetric dimethylarginine (ADMA). Aim-To examine the effect of renal function and dialysis on the serum concentrations of ADMA and symmetric dimethylarginine (SDMA), Methods-Blood samples were obtained fi om nine healthy subjects, patients with renal failure before (n = 17) and after haemodialysis (n = 9), nine patients on chronic ambulatory peritoneal dialysis (CAPD),and 13 patients with chronic renal failure on conservative treatment. Serum samples were extracted using a solid phase cation exchange column and the extracts were analysed by high performance liquid chromatography (HPLC). Results-Serum concentrations of ADMA in patients with renal failure (mean, 1.04 mu mol/litre; SD, 0.17) were significantly higher than those of controls (mean, 0.61 mu mol/litre; SD, 0.13). Haemodialysis significantly decreased the serum concentration by 36% (before dialysis: mean 0.99 (SD, 0.25) mu mol/litre; after dialysis: mean, 0.63 (SD, 0.15) mu mol/litre). Serum SDMA concentrations were higher in patients with renal failure, and haemodialysis decreased the concentration by 60%. There was no difference in serum arginine concentrations between the groups. Conclusion-Serum concentrations of ADMA are increased in renal failure and haemodialysis reduces the concentration.