In vivo canine gut segments perfused by branches of the superior mesenteric artery were subjected to increased intraluminal pressure to observe the effects upon arterial inflow, measured with an electromagnetic blood flowmeter, and venous effluent collected by a cannula. Inflation of the intestinal segment with air simultaneously reduced both inflow and outflow. Intra-arterial infusion of acetylcholine increased blood flow, even with intraluminal pressure maintained at 40 mm Hg. Mechanical distension of the gut impedes blood flow, but this effect can be overridden by a vasodilator. These findings correspond to results observed in similar experiments on in vitro gut segments.
展开▼
