[L-arginine nitric oxide pathway in acute renal ischemia reperfusion injury of the aged rats].
OBJECTIVE
To gain further insights into the greater susceptibility to acute ischemic renal injury (ARF, 45 minutes of renal arteries clamping) of old rats (O, 24-26 months) as against young ones (Y, 3-4 months), and the possible role of endothelium derived relaxing factor (EDRF) and its influence on ischemic renal function.


METHODS
Basal renal dynamics was compared between O and Y.


RESULTS
Two hours after ischemia, the decrease of GFR RPF, and UV was more severe in O than in Y. Urine cGMP was significantly dropped in both groups. Intravenous administration of L-arginine increasld urine cGMP of the O as well as the Y, with that of the Y higher than that in O. GFR, RPF, UV were elevated significantly in the O. Simultaneous administration of L-NNA, the analogue of L-Arginine could partially antagonize its effect on elevating RPF. RT-PCR technique was used to detect renal inducible nitric oxide synthase (iNOS) expression. Although the ischemic kidney was capable of expressing iNOS mRNA in the presence of L-arginine after ischemia, the production of NO in the old may not be regulated at the transcriptional level, other factors such as NOS enzyme activity, availability of L-arginine and O2, metabolism of NO after its production were suspected to be involved.
Chen
A
A
Institute of Nephrology, Beijing Medical University, P. R. China.
Lu
X
X
Wang
H
H
D000375:Aging; D000818:Animals; D001120:Arginine / Q000494:pharmacology; D006152:Cyclic GMP / Q000652:urine*; D007511:Ischemia / Q000378:metabolism*; D007668:Kidney / Q000098:blood supply*; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000096:biosynthesis; D051381:Rats; D017208:Rats, Wistar; D012076:Renal Agents / Q000494:pharmacology; D015427:Reperfusion Injury / Q000378:metabolism*
D012076:Renal Agents; D009569:Nitric Oxide; D001120:Arginine; D019001:Nitric Oxide Synthase; D006152:Cyclic GMP