AMINO-ACID PROFILE AND NITRIC-OXIDE PATHWAY IN PATIENTS ON CONTINUOUSAMBULATORY PERITONEAL-DIALYSIS - L-ARGININE DEPLETION IN ACUTE PERITONITIS

To gain insights into the amino acid metabolism and L-arginine-nitric oxide system, we studied 21 control continuous peritoneal dialysis (CP D) patients and 13 patients with 15 episodes of acute peritonitis. The concentrations of amino acids, including L-arginine, were measured in the peritoneal dialysate and in the serum. The data demonstrate that patients with end-stage renal disease on CPD who have acute peritoniti s develop L-arginine deficiency. The majority of patients with acute b acterial peritonitis have increased nitric oxide production as judged by the level of nitrites in the dialysate. The recovery from peritonit is is associated with a decline in nitric oxide generation. Paradoxica lly, there is a smaller subgroup of these patients that shows low nitr ite levels during acute peritonitis. The nitrite to L-arginine ratio i n the peritoneal dialysate is increased in patients with peritonitis, further suggesting the development of substrate deficiency. These find ings implicate L-arginine as a conditionally essential amino acid in C PD patients with acute peritonitis and raise questions concerning the necessity of L-arginine supplementation. (C) 1997 by the National Kidn ey Foundation, Inc.