Effects of nitric oxide synthesis inhibition on FK506-induced nephrotoxicity in rats.
This study was designed to evaluate the role of nitric oxide (NO) in FK506-induced nephrotoxicity by administering an inhibitor of NO synthesis, N omega-nitro-L-arginine methyl ester (L-NAME) to rats treated with FK506. After one week of treatment with FK506 (3.2 mg/kg/day, intramuscularly) and/or L-NAME (5 mg/100 mL of L-NAME in the drinking water), the arterial pressure, urinary NOx, and parameters for renal function were measured, and histological analysis of the kidney was made. In the L-NAME without FK506 group, L-NAME administration effectively inhibited urinary NOx excretion and increased mean arterial pressure (MAP) without any change in renal function. In the FK506 without L-NAME group, FK506 treatment showed increase in urinary NOx excretion and mild renal dysfunction. In the FK506 with L-NAME group, urinary NOx excretion was decreased by L-NAME administration and renal function was significantly worsened than FK506 without L-NAME group. The plasma creatinine, BUN and urinary N-acetyl-beta-D-glucosaminidase increased 2-, 3-, and 3-fold, respectively and the creatinine clearance was reduced by 50% as compared with that in the FK506 without L-NAME group. Histological analysis revealed severe interstitial fibrosis and tubular atrophy in the FK506 + L-NAME treatment group. Thus, results suggest that NO synthesis is enhanced in the kidney during FK506-induced nephrotoxicity and that NO synthesis inhibition aggravates FK506-induced nephrotoxicity. NO may play a protective role attributable to the balance of vasoactive substances in FK506-induced nephrotoxicity.
Wang
L
L
Department of Urology, Yamanashi Medical University, Tamaho, Japan. wangl@res.yamanashi-med.ac.jp
Kubodera
S
S
Ueno
A
A
Takeda
M
M
D000818:Animals; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D007166:Immunosuppressive Agents; D007674:Kidney Diseases / Q000139:chemically induced* / Q000378:metabolism; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology*; D009569:Nitric Oxide / Q000037:antagonists & inhibitors / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors*; D051381:Rats; D017208:Rats, Wistar; D016559:Tacrolimus
D004791:Enzyme Inhibitors; D007166:Immunosuppressive Agents; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D019331:NG-Nitroarginine Methyl Ester; D016559:Tacrolimus