Superior mesenteric blood flow during experimentally induced dumping in man.

The superior mesenteric circulation was studied with a dye-dilution technique after catheterization of the superior mesenteric artery and vein during provoked dumping in 5 patients. Dumping was provoked by intrajejunal instillation of 150 ml 50% glucose. A marked increase of, on the average, 157% was recorded in the superior mesenteric blood flow within a few minutes of the installation of glucose. The maximal increase in the flow was, on the average, 223% and occurred about 40 minutes after provocation. The instillation of glucose was promptly followed by a reduction in vascular resistance of the superior mesenteric vessels by 63% which decreased further to a mean maximal reduction of 76% below the resting level. The increase in the ratio between the superior mesenteric blood flow and cardiac output from 12 to 27% following instillation of glucose further underlines the pronounced vasodilatation of the small intestine. Superior mesenteric angiography at different intervals after provocation of dumping showed that the increased superior mesenteric blood flow is due to a local increase in the flow.