Primate mesenteric blood flow. Effects of vasopressin and its route of delivery

The effects of vasopressin on blood flow in the superior mesenteric artery and on mean arterial pressure and portal venous pressure were measured in 7 rhesus monkeys. Vasopressin was injected, as either a bolus, or infused both intravenously and intraarterially to assess the influence of the route of administration upon hemodynamic responses. Dose-dependent decreases in superior mesenteric arterial flow were observed during both intraarterial and intravenous injections of vasopressin. No statistically significant differences between the two routes of administration, the decrease in flow, and changes in pressure were observed. Based upon these observations, one might anticipate that intravenously administered vasopressin will be as effective as intraarterially administered vasopressin in reducing mesenteric blood flow, and thus portal venous pressure, in man.