Abstract
The effects of 30-min i.v. and superior mesenteric artery (SMA) infusions of vasopressin in dosages of 2.75 mU and 14 mU per min per kg were compared in 5 dogs that had cirrhosis and portal hypertension induced by fractionated intraportal polyvinyl alcohol injections. A reduction in portal pressure of .apprx. 35% was found with both SMA doses and the larger i.v. vasopressin dose, while the smaller i.v. dose reduced portal pressure only 18%. A significantly larger decrease in portal blood flow was found with SMA than i.v. vasopressin administration. Cardiovascular side effects were dose-dependent but independent of the administration mode. Liver enzymes were unaffected. Portal vein thrombosis occurred in 1 dog after the larger SMA dose.