AJP - Regulatory, Integrative and Comparative Physiology, Vol 251, Issue 1 181-R186, Copyright © 1986 by American Physiological Society
Suppression of plasma renin and aldosterone in stress-salt hypertension in dogs
D. E. Anderson, C. Gomez-Sanchez and J. R. Dietz
Plasma renin activity (PRA) and plasma aldosterone concentrations (PAC) of
12 intact chronically instrumented dogs were measured at midday after 1)
7-12 days of normal sodium intake and no behavioral stress, 2) 7-12 days of
continuous saline infusion (1.34 l/day) only, and/or 3) 7-12 days of saline
infusion and avoidance-conditioning sessions. The saline infusion procedure
did not significantly change arterial pressure or heart rate relative to
base line but was associated with a consistent decrease in PRA (-0.90 +/-
0.38 ng angiotensin I . ml-1 . h-1) and PAC (-3.6 +/- 1.1 ng/dl). The
combination of saline infusion and avoidance conditioning resulted in
significant elevations in arterial pressure, but, again, both PRA (-1.46
+/- 0.16 ng angiotensin I . ml-1 . h-1) and PAC (-3.7 +/- 1.1 ng/dl) were
significantly decreased. These results show that high sodium intake
decreased aldosterone via suppression of renin release but do not rule out
a possible hypertensinogenic role for stress-induced adrenocorticotrophic
hormone-sensitive corticoids.
