AJP - Renal Physiology, Vol 245, Issue 1 119-F122, Copyright © 1983 by American Physiological Society
Alteration of renal baroreceptor by salt intake in control of plasma renin activity in conscious dogs
E. R. Farhi, J. R. Cant and A. C. Barger
We investigated the relationship between renal arterial pressure (RAP) and
systemic plasma renin activity (PRA) in five uninephrectomized conscious
dogs on normal salt (80 meq Na+/day) and low salt (10 meq Na+/day) diets.
The RAP was controlled by an inflatable cuff placed around the origin of
the renal artery. In both salt states the PRA was an exponential function
of the RAP: log (PRA) = (-0.026 X RAP) + 2 on the normal salt diet (r =
0.96) and log (PRA) = (-0.026 X RAP) + 2.5 on the low salt diet (r = 0.99).
At any RAP, the value of the low salt PRA was 3 times that of the normal
salt PRA. Accordingly, a reduction in salt intake increases the sensitivity
of the renal baroreceptor so that the absolute value of PRA increases at
any RAP, but the percentage change in PRA caused by any change in RAP is
the same in both normal and low salt states.
