Nitric oxide and renal nerve-mediated proximal tubular reabsorption
in normotensive and hypertensive rats.
Wu, Xiao Chun, Peter J Harris and Edward J Johns.
1Department of Physiology, The Medical School, Birmingham B15 2TT,
United Kingdom, and 2Department of Physiology, University of
Melbourne, Parkville, Victoria 3052, Australia.
APStracts 6:0124F, 1999.
In Inactin anaesthetised Wistar rats with an intact renal innervation,
intratubular L-NAME (10-4M) increased proximal fluid uptake (Jva, at
2.47 +/- 0.61 x 10-4 mm3 mm2 s-1) by 17% (P<0.05) whereas co
-administration with sodium nitroprusside (SNP, 10-4M) decreased Jva
by 18% (P<0.01). Similar manipulation of NO generation was without
effect in groups of Wistar rats subjected to acute renal denervation.
Intratubular aminoguanidine (10-4M), a selective inducible NOS
blocker, had no effect on Jva in intact kidneys of Wistar rats, but
the neuronal NOS blocker, 7-nitroindazole (10-4M and 10-6M) increased
Jva by 19-23% (both P<0.001). In stroke prone spontaneously
hypertensive rats (SHRSP), Jva in the innervated kidneys were lower
(P<0.05) than in the corresponding Wistar groups and was unchanged
by intratubular L-NAME or L-NAME plus SNP. The tonic attenuation of
proximal epithelial transport by NO was dependent on the renal
sympathetic nerves and appeared to be generated by an nNOS isoform of
the enzyme. This role of NO was not evident in the SHRSP.
Received 25 January 1999; accepted in final form 26 May 1999.
APS Manuscript Number F015-9.
Article publication pending Am. J. Physiol. (Renal Physiology).
ISSN 1080-4757 Copyright 1999 The American Physiological Society.
Published in APStracts on 25 June 1999