We studied the effect of vasopressin, infused continually via the superior mesenteric artery, on the hemodynamics of the portal venous system. Superior mesenteric venous blood flow decreased with statistical difference, as did portal venous blood flow and portal venous pressure. However, splenic venous blood flow did not decrease significantly and there were even some cases in which an increase was apparent, despite the decrease in cardiac output, which is considered to be a systemic side

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... systemic side effect arising from the use of vasopressin. We suspect there was a increase in the splenic venous flow to compensate for the decrease, caused by the infusion of vasopressin, in the superior mesenteric venous blood flow. The changes in O2 content of the superior mesenteric and splenic veins indicated the same phenomena as indicated by the blood flow measurements.