Recent work published by this laboratory in the subhuman primate has demonstrated that the primary cause of the decrease in mean systemic arterial pressure following a lethal injection of endotoxin is a decrease in venous return.1 However, a marked difference in response to endotoxin is observed in monkeys in contrast to dogs. In the former, a gradual fall in mean systemic arterial pressure is observed, and there is neither demonstrable pooling in the hepatosplanchnic bed nor loss of circulating blood to extravascular compartments.1-5
The cause of the decrease in venous return in the primate has not been determined. A previous study did not differentiate between a decrease in venous return due to peripheral pooling or failure of cardiac contractility.1 The cardiac output in some human patients shows a steady decline,6,7 although there is no evidence of primary cardiac failure in man6 or the nonhuman primate.
Hinshaw LB, Shanbour LL, Greenfield LJ, Coalson JJ. Mechanism of Decreased Venous ReturnSubhuman Primate-Administered Endotoxin. Arch Surg. 1970;100(5):600-606. doi:10.1001/archsurg.1970.01340230066017