L-arginine supplementation in young renal allograft recipients with chronic transplant dysfunction.
OBJECTIVE
L-arginine (LA), the precursor of nitric oxide (NO), was suggested to be beneficial in many forms of renal disease: hypertension, ureteral obstructive nephropathy and cyclosporin A (CsA) nephrotoxicity.


METHODS
Thus, we investigated the effects of LA supplementation on renal function, proteinuria and blood pressure (BP) in young renal allograft recipients with chronic renal transplant dysfunction treated with CsA. Eleven CsA-treated renal allograft recipients with chronic transplant dysfunction, aged 11-22 years, were randomly assigned to a 6-week treatment period with placebo (P), followed by 2 subsequent 6-week periods with LA supplementation (0.1 g/kg body weight/day) or a 6-week treatment period with LA, followed by 2 subsequent 6-week periods with P. At the end of each treatment period 24-hour BP recordings were made, and GFR (Inutest), RPF (PAH clearance) and the urinary excretion of protein, albumin, nitrate, cGMP and urea were evaluated.


RESULTS
In comparison to placebo, LA treatment did not significantly change GFR, RPF, proteinuria and albuminuria, mean systolic or diastolic BP. The urinary excretion of urea and NO3 increased after LA supplementation (uUrea: LA 26.3 +/- 4.6 compared to P 23.5 +/- 4.7 g/day/1.73 m3, p < 0.05, uNO3: LA 514 +/- 152 compared to P 95 +/- 41 mM/day/1.73 m3, p < 0.05), whereas urinary excretion of cGMP remained unchanged.


CONCLUSIONS
LA supplementation did not improve renal function and did not decrease proteinuria in CsA-treated renal allograft recipients with chronic transplant dysfunction possibly because of inhibition of NO-cGMP forming mechanism.
Zhang
X Z
XZ
Department of Pediatrics I, University of Milan, Italy.
Ardissino
G
G
Ghio
L
L
Tirelli
A S
AS
Daccò
V
V
Colombo
D
D
Pace
E
E
Testa
S
S
Claris-Appiani
A
A
D000293:Adolescent; D001120:Arginine / Q000627:therapeutic use*; D002648:Child; D016572:Cyclosporine / Q000627:therapeutic use; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D016030:Kidney Transplantation / Q000502:physiology*; D008297:Male; D013997:Time Factors
D007166:Immunosuppressive Agents; D016572:Cyclosporine; D001120:Arginine