Effects of endotoxin on the hemodynamics of the stomach.

Endotoxin induces many profound vascular effects, including venous pooling, changes in resistance to blood flow in many organs, and circulatory collapse leading to death. Prominent among the early vascular effects of endotoxin is the rapid development of hepatic and intestinal congestion (2-4). One apparent mechanism of splanchnic blood pooling in endotoxin shock is hepatic venoconstriction. Liver engorgement subsides with time, but intestinal venous congestion continues, suggesting some persistent effects of endotoxin. either directly on the blood vessels of the gut, or indirectly on these vessels through nervous or humoral mechanisms (2, 5, 6). The gastric circulation, like the intestinal, is in direct continuity with the portal vein and might be expected to exhibit responses to endotoxin similar to those of the gut vasculature. In order to differentiate the direct hemodynamic effects of endotoxin from indirect neurohumoral influences on the circulation of the stomach, the gastric vasculature was studied both in continuity with the general circulation and as an isolated vascular bed.