Effect of a perinatal high-salt diet on blood pressure control mechanisms in young Sprague-Dawley rats
Document Type
Article
Publication Date
4-1-2004
Publication Title
American Journal of Physiology - Regulatory, Integrative and Comparative Physiology
ISSN
0363-6119
Volume
286
Issue/No.
4
First Page
R764
Last Page
70
Abstract
In the present investigation we sought to determine if a perinatal high-salt treatment affects blood pressure at an early age (30 days), and if so, to determine the mechanisms responsible for the hypertension. Pregnant dams were given an 8% NaCl diet [high-salt (HS) rats] during the final one-third of gestation and throughout the suckling period. After weaning, the pups continued to receive the high-salt diet until testing at age 30 days. Control groups received a normal-salt diet (NS rats). In HS rats, mean arterial pressure (MAP) was significantly increased (110 +/- 5 vs. 96 +/- 3 mmHg) compared with NS rats. Blockade of brain AT(1) receptors with intracerebroventricular losartan decreased MAP in HS but not NS rats. Blockade of alpha-adrenergic receptors with intravenous phentolamine or ganglionic transmission with intravenous chlorisondamine produced a greater decrease in MAP in HS rats. Baroreflex control of heart rate was assessed using a four-parameter logistics function. The mid-range MAP (p3) was significantly increased in the HS rats. No other baroreflex parameters were affected. Specific binding of (125)I-[Sa (1),Ile(8)]ANG II to AT(1) receptors was increased in the subfornical organ (SFO) of the HS rats. Expression of AT(1a) receptor mRNA was greater in both SFO and PVN of the HS rats. These data suggest that even at an early age, Sprague-Dawley rats treated with a perinatal high-salt diet are hypertensive. The elevated blood pressure appears to be caused by increased sympathetic nervous activity, resulting, in part, from increased brain AT(1) receptor activation.
NSUWorks Citation
Swenson, Steven J.; Speth, Robert C.; and Porter, James P., "Effect of a perinatal high-salt diet on blood pressure control mechanisms in young Sprague-Dawley rats" (2004). HPD Articles. 60.
https://nsuworks.nova.edu/hpd_facarticles/60
ORCID ID
0000-0002-6434-2201
DOI
10.1152/ajpregu.00492.2003
Copyright
Copyright © 2004 the American Physiological Society
