AJP - Heart and Circulatory Physiology, Vol 249, Issue 3 577-H584, Copyright © 1985 by American Physiological Society
Prevention of fatal hemorrhagic shock in dog by pretreatment with chronic high-salt diet
A. P. Rocchini, K. P. Gallagher, M. J. Botham, J. H. Lemmer, C. A. Szpunar and D. Behrendt
The ability of a chronic high-salt diet to prevent fatal hemorrhagic shock
was examined in 36 mongrel dogs. Twenty-one dogs received a dietary
supplement of 9 g sodium chloride/day for 6 wk, and 15 dogs received the
same basic diet for 6 wk but without the sodium chloride supplement.
Hemorrhagic shock was induced in all dogs by bleeding into an overhanging
sealed reservoir. After 3 h of shock, salt-pretreated dogs had a lower
systemic vascular resistance of 0.70 +/- 0.02 versus 1.44 +/- 0.04 mmHg X
ml-1 X min X kg (P less than 0.01) and a higher cardiac output of 53 +/- 3
versus 26 +/- 3 ml X min-1 X kg-1 (P less than 0.01) than was observed in
controls. At 2.5 h of shock, the salt-pretreated dogs also experienced an
increase in gastrointestinal (P less than 0.01), hepatic arterial, (P less
than 0.05), kidney (P less than 0.05), brain (P less than 0.01), and heart
blood flows (P less than 0.001) compared with 0.5 h of shock, whereas the
control dogs experienced no increased flow during this same period. We also
observed that after 3 h of hypotension there was a significantly smaller
increase in plasma renin activity in the salt-pretreated dogs.
Administration of 0.1 U X kg-1 X min-1 of hog renin eliminated the
differences in systemic vascular resistance, cardiac output, and survival
in five salt-pretreated dogs.
