AJP - Regulatory, Integrative and Comparative Physiology, Vol 262, Issue 5 733-R737, Copyright © 1992 by American Physiological Society
Renal nerves contribute to salt-induced hypertension in sinoaortic-denervated uninephrectomized rabbits
M. Ryuzaki, H. Suzuki, K. Kumagai, H. Kumagai, M. Ichikawa, S. Matsukawa, Y. Matsumura and T. Saruta
Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan.
The objective of this study was to investigate the role of the renal nerves
in the pathogenesis of salt-induced hypertension in sinoaortic-denervated
uninephrectomized rabbits. Twelve rabbits were divided into two groups.
Sinoaortic-denervated uninephrectomized rabbits with intact renal nerves
(sham group: n = 6) and without renal nerves (RDN group; n = 6). In both
groups, 2 days of 154 meq/l NaCl loading was followed by 10 days of 1,700
meq/l NaCl loading. We administered 154 meq/l or 1,700 meq/l NaCl
intravenously at every 8 h. Serial changes in mean arterial pressure (MAP)
and heart rate (HR) were recorded using a microcomputer system. We
chronologically measured hematocrit, serum osmolality, serum sodium,
potassium, and chloride concentration, serum creatinine, plasma renin
activity, plasma aldosterone, plasma norepinephrine, plasma arginine
vasopressin, and plasma atrial natriuretic peptide. Urine volume and body
weight were recorded every day, as were urinary concentrations of sodium,
potassium, and chloride. The basal value of MAP in the sham group was
significantly higher than that in the RDN group (on day -2, 111 +/- 1 mmHg
for sham, 99 +/- 2 for RDN, P less than 0.001). Hypertonic saline loading
induced an elevation of blood pressure in the sham group (126 +/- 2 mmHg on
day 4, 127 +/- 2 on day 7, 124 +/- 4 on day 10). There were no significant
changes in the response to salt loading in the RDN group. In the sham
group, the retention of sodium was significant compared with that in the
RDN group on day 5, and this difference was maintained until the end of the
experiments.(ABSTRACT TRUNCATED AT 250 WORDS)
