We tested the hypothesis that gender and daily spontaneous running (DSR) influence the arterial baroreflex regulation of heart rate (HR) and lumbar sympathetic nerve activity (LSNA). The arterial baroreflex regulation of HR and LSNA was examined in thirteen male (7 sedentary, SED and 6 DSR) and twelve female (6 SED and 6 DSR) Sprague-Dawley rats. All animals were chronically instrumented with femoral venous and left carotid arterial catheters and electrodes around the lumbar sympathetic trunk. Eight to nine weeks of DSR resulted in a significant increase in heart weight-to-body weight ratio for female (18%) and male (14%) rats. DSR also decreased resting heart rate for male rats (21%). The range, gain, and maximum of the arterial baroreflex regulation of HR (25%, 38%, and 12%, respectively) and LSNA (32%, 46%, and 26%, respectively) were reduced in DSR female rats. There was a downward shift and reduced maximum HR (17%) and a reduced range (29%) and maximum (21%) of the arterial baroreflex regulation of LSNA in DSR male rats. The gain (40%) and range (23%) of the arterial baroreflex regulation of HR were significantly higher in SED female versus SED male rats. However, there were no gender differences in the arterial baroreflex regulation of HR in the DSR rats. These results demonstrate that: 1 ) the arterial baroreflex regulation of LSNA and HR was reduced by DSR. 2) SED female rats had a higher gain and range of the arterial baroreflex regulation of HR than SED male rats. 3) DSR normalized arterial baroreflex function in male and female rats.
|Original language||English (US)|
|State||Published - 1996|
ASJC Scopus subject areas
- Agricultural and Biological Sciences (miscellaneous)
- Biochemistry, Genetics and Molecular Biology(all)
- Cell Biology