Title

Cardiovascular effects of daily volitional exercise in Dahl-salt sensitive rats

ORCID

J. Mark VanNess: https://orcid.org/0000-0001-5902-8735

Document Type

Article

Publication Title

American Journal of Hypertension

Department

Health, Exercise, and Sport Sciences Department

ISSN

0895-7061

Volume

11

DOI

10.1016/S0895-7061(97)00308-7

First Page

73

Last Page

80

Publication Date

1-1-1998

Abstract

We tested the hypothesis that daily exercise would reduce directly measured arterial blood pressure (BP) and sympathetic nervous system support of BP in conscious, unrestrained, female Dahl salt-sensitive rats consuming 4.0% NaCl. Dahl S/Jr inbred rats were assigned to daily exercise (EX) or sedentary (SED) treatment conditions (n = 12/group) at 4 weeks of age. Rats in the EX group were housed in cages with attached running wheels. After 5 weeks of exercise, rats were running 10.3 ± 1.7 km/day. After at least 5 wks of treatment, all rats in both groups were placed on a 4.0% NaCl diet for 2 weeks to produce sodium-induced hypertension. Rats continued to either exercise daily or remain sedentary for an additional 2 weeks while consuming the high sodium diet. Carotid and jugular catheters were then implanted for measurements in conscious, resting, unrestrained rats on two separate days. Daily wheel running exercise for 7 to 9 weeks did not alter BP or HR in Dahl S/Jr rats consuming a 4.0% NaCl diet. However, acute arterial depressor responses to ganglionic blockade were less in EX rats. Furthermore, greater α-adrenergic (phenylephrine-induced) pressor responses were observed in the EX group while under ganglionic blockade. The findings suggest that overall resting sympathetic neural activity or cardiac β-adrenergic responsiveness to sympathetic activity is reduced in this model of hypertension by daily wheel running exercise.

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