RENAL DENERVATION CAUSES CHRONIC HYPOTENSION IN RATS: ROLE OF
1-ADRENOCEPTOR ACTIVITY
Authors: Jacob, Frédéric1; LaBine, Brian G1; Ariza, Pilar1; Katz, Stephen A1; Osborn, John W1
Source: Clinical and Experimental Pharmacology and Physiology, Volume 32, Number 4, April 2005 , pp. 255-262(8)
Publisher: Blackwell Publishing
Abstract:
SUMMARY 1. Renal denervation (RDNX) chronically lowers mean arterial pressure (MAP) in normal rats but mechanisms leading to this hypotensive response remain unknown.2. We hypothesized that this sustained decrease in arterial pressure was because of a loss of
1-adrenoceptor mediated renin secretion. Male Sprague-Dawley rats were assigned to sham (SHAM; n = 9), unilateral (UniRDNX; n = 9), or bilateral (RDNX; n = 10) renal denervation groups and instrumented for telemetric MAP measurements, plasma renin concentration (PRC) measurements and intravenous infusion. Twenty-four h MAP, heart rate, sodium and water balances were recorded 5 days before, 3 days during and 3 days after 1-adrenoceptor blockade with atenolol. 3. The 5-day control MAP was significantly lower in RDNX (97 ± 1 mmHg) compared to SHAM (105 ± 2 mmHg) and UniRDNX (102 ± 2 mmHg) rats. No significant differences in basal PRC were observed between RDNX (2.2 ± 0.3 ngAng1/mL per h), UniRDNX (2.6 ± 0.4 ng/Ang1/mL per h) and SHAM (2.6 ± 0.4 ngAng1/mL per h) rats. By day 1 of atenolol, PRC was significantly lower in UniRDNX rats (1.8 ± 0.2 ngAg1/mL per h) compared to control values, but was unchanged during atenolol infusion in the other groups. By day 3 of atenolol, MAP was significantly decreased in all groups, but the absolute levels of MAP remained statistically different between RDNX (87 ± 1 mmHg) and SHAM (91 ± 1 mmHg) groups.4. We conclude that the arterial pressure lowering effect of RDNX is not solely dependent on the loss of neural control of renin release.
Keywords:
arterial pressure;
1-adrenergic blockade;
plasma renin concentration;
renal denervation;
Sprague-Dawley rats
Document Type: Research article
DOI: 10.1111/j.1440-1681.2005.04179.x
Affiliations: 1: Department of Physiology, Lillehei Heart Institute, University of Minnesota, Minneapolis, MN, USA

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