AJP - Regulatory, Integrative and Comparative Physiology, Vol 250, Issue 1 18-R23, Copyright © 1986 by American Physiological Society
Corticosteroids and plasma restitution after hemorrhage and hypothalamic lesions
S. L. Bealer
The effects of electrolytic ablation of the anteroventral portion of the
third ventricle (AV3V) on plasma volume (PV) restitution and adrenal
corticosteroid responses after hemorrhage were determined. After recovery
from AV3V ablation or control surgeries, animals were implanted with a
catheter in the femoral artery. PV was determined before and either 2 or 24
h after moderate hemorrhage (1.4% body wt for controls; 1.3% body wt for
AV3V lesion) by calculating dilution of 125I-labeled serum albumin. Other
rats with AV3V lesions and control animals were used to measure
concentrations of renin, aldosterone, and corticosterone 0.5 or 2 h after
similar hemorrhage. The percent of shed PV restored was similar in rats
with AV3V lesions and control-operated animals both 2 and 24 h after
hemorrhage. Furthermore, the restitution of plasma protein mass was not
different. Rats with AV3V lesions showed a similar increase in plasma renin
concentration after hemorrhage, but they showed a smaller increase in the
concentration of plasma aldosterone and no increase in the concentration of
plasma corticosterone. These data demonstrate that electrolytic ablation of
AV3V periventricular tissue does not alter either the short- or long-term
phase of PV restitution, even though concentrations of plasma
corticosterone are not increased.
