Journal of Applied Physiology, Vol 52, Issue 6 1608-1613, Copyright © 1982 by American Physiological Society
Attenuation of blood pressure increases in Dahl salt-sensitive rats by exercise
R. E. Shepherd, M. L. Kuehne, K. A. Kenno, J. L. Durstine, T. W. Balon and J. P. Rapp
Systolic blood pressure was determined weekly to assess the development of
hypertension in sedentary and active Dahl salt-sensitive (S) rats that were
exercised by running at 20 m/min, 60 min/day, 5 days/wk. The marked rise in
blood pressure that occurred with feeding 8% NaCl (wt/wt) diet in Dahl S
rats could be attenuated by chronically practiced endurance running, but
only if exercise at 20 m/min was started at the beginning of salt feeding.
Under the same dietary feeding conditions, running at 27 m/min resulted in
incomplete attenuation of hypertension. Further, running for 30 min/day was
not as beneficial as running 60 min/day at 20 m/min. Delaying the start of
exercise for 6 wk after the beginning of salt feeding did not result in
reduction of hypertension in the S rat. These experiments indicate that
increases in blood pressure can be prevented in Dahl S rats for 12 wk if
running is initiated concomitantly with salt feeding. Blood pressure is not
reduced if hypertension due to salt feeding has been continued for 6 wk.
The results also indicate that there is an optimal exercise intensity,
duration, or both, for controlling hypertension in Dahl rats.
