Cardiac and renal effects induced by different exercise workloads in renovascular hypertensive rats

ABSTRACT

We examined the effect of exercise training (Ex) without (Ex 0 percent) or with a 3 percent workload (Ex 3 percent) on different cardiac and renal parameters in renovascular hypertensive (2K1C) male Fisher rats weighing 150-200 g. Ex was performed for 5 weeks, 1 h/day, 5 days/week. Ex 0 percent or Ex 3 percent induced similar attenuation of baseline mean arterial pressure (MAP, 119 ± 5 mmHg in 2K1C Ex 0 percent, N = 6, and 118 ± 5 mmHg in 2K1C Ex 3 percent, N = 11, vs 99 ± 4 mmHg in sham sedentary (Sham Sed) controls, N = 10) and heart rate (HR, bpm) (383 ± 13 in 2K1C Ex 0 percent, N = 6, and 390 ± 14 in 2K1C Ex 3 percent, N = 11 vs 371 ± 11 in Sham Sed, N = 10,). Ex 0 percent, but not Ex 3 percent, improved baroreflex bradycardia (0.26 ± 0.06 ms/mmHg, N = 6, vs 0.09 ± 0.03 ms/mmHg in 2K1C Sed, N = 11). Morphometric evaluation suggested concentric left ventricle hypertrophy in sedentary 2K1C rats. Ex 0 percent prevented concentric cardiac hypertrophy, increased cardiomyocyte diameter and decreased cardiac vasculature thickness in 2K1C rats. In contrast, in 2K1C, Ex 3 percent reduced the concentric remodeling and prevented the increase in cardiac vasculature wall thickness, decreased the cardiomyocyte diameter and increased collagen deposition. Renal morphometric analysis showed that Ex 3 percent induced an increase in vasculature wall thickness and collagen deposition in the left kidney of 2K1C rats. These data suggest that Ex 0 percent has more beneficial effects than Ex 3 percent in renovascular hypertensive rats.