Nitric oxide and renal effects of volume expansion in conscious
monkeys.
Peterson, Thomas V., Alice B. Carter, and Rhonda A. Miller.
Department of Medical Physiology, Texas A&M University Health
Science Center, College Station, Texas 77843-1114
APStracts 3:0398R, 1996.
Experiments were performed to determine the effects of nitric oxide
(NO) synthase inhibition on the renal responses to volume expansion
in conscious cynomolgus monkeys. All animals were volume-expanded
with 3% dextran in normal saline under three conditions: 1) a control
state, 2) during constant infusion of the NO synthase inhibitor
nitro-L-arginine methylester (L-NAME, 30 [mu]g/kg/min) and 3) during
simultaneous infusion of L-NAME and excess NO substrate L-arginine
(0.6 mg/kg/min). The control volume expansion increased urine flow
from 0.27+/-0.05 to 0.94+/-0.28 ml/min and sodium excretion from
21+/-9 to 95+/-26 [mu]Eq/min. During L-NAME infusion, these responses
were attenuated in that urine flow only increased from 0.13+/-0.03 to
0.28+/-0.09 ml/min and sodium excretion from 13+/-8 to 35+/-23
[mu]Eq/min. Addition of L-arginine to the L-NAME infusion abolished
these renal excretory effects of L-NAME alone. With combined L
-NAME/L-arginine, volume expansion increased urine flow from 0.37+/
-0.23 to 1.09+/-0.23 ml/min and sodium excretion from 38+/-27 to
150+/-24 [mu]Eq/min, responses similar to control. L-arginine also
markedly attenuated the effect of L-NAME to increase mean arterial
pressure and abolished the L-NAME decreases in creatinine and para
-aminohippurate clearances. However, an L-NAME-induced bradycardia
could only be partially reversed. These results demonstrate that a
functioning NO system may be important in mediating normal renal
responses to volume expansion in this primate species.
Received 8 December 1995; accepted in final form 24 September
1996.
APS Manuscript Number R779-5.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 31 December 1996