AJP - Regulatory, Integrative and Comparative Physiology, Vol 264, Issue 6 1254-R1259, Copyright © 1993 by American Physiological Society
Role of endothelium-derived nitric oxide in hemodynamic adaptations after graded renal mass reduction
K. A. Griffin, A. K. Bidani, J. Ouyang, V. Ellis, M. Churchill and P. C. Churchill
Department of Internal Medicine, Loyola University Medical Center, Maywood, Illinois.
The mediator(s) of the adaptive increases in renal blood flow (RBF) and
glomerular filtration rate (GFR) after renal mass reduction have not been
identified. The present studies were designed to investigate the role of
endothelium-derived nitric oxide (EDNO) in the hemodynamic adaptations
after graded renal mass reduction. The experiments were performed in rats
that had undergone a sham reduction in renal mass, uninephrectomy (UNX), or
5/6 NX (UNX plus excision of both poles of the contralateral kidney) 3-4 wk
before. Measurements of RBF, GFR, renal vascular resistance (RVR), mean
arterial pressure (MAP), and plasma renin concentration (PRC) were obtained
before and after administration of the EDNO synthesis inhibitor
NG-monomethyl-L-arginine (L-NMMA). L-NMMA (50 mg/kg bolus plus 500
micrograms.kg-1.min-1 infusion) led to significant (P < 0.01) and
comparable increases in MAP (mmHg) (P < 0.01) in sham rats (117 +/- 6 to
154 +/- 6), UNX rats (112 +/- 5 to 139 +/- 7), and 5/6 NX rats (116 +/- 5
to 149 +/- 7). RVR increased significantly in all three groups (P <
0.01). The resultant decrease in RBF (ml.min-1.kg-1) was similar in sham
rats (34.9 +/- 2.6 to 23.8 +/- 1.6), UNX rats (43.9 +/- 3.6 to 27.3 +/-
2.8), and 5/6 NX rats (34.6 +/- 2 to 22.3 +/- 1.6) (P < 0.01 for all
groups).(ABSTRACT TRUNCATED AT 250 WORDS)
