Effects of intra-arterial phentolamine in experimental intestinal ischaemia in the rabbit

Abstract A loop of ileum on its mesentery was withdrawn from the abdomen of the anaesthetized rabbit and kept warm and moist. This induced intestinal ischaemia, as judged by the external appearances of the bowel and by superior mesenteric angiography, in 32 out of 52 animals. Ischaemia was treated by infusing phentolamine into the superior mesenteric artery. Large doses (2 mg per kg bodyweight) consistently produced marked improvement in angiographic and naked eye appearances. Smaller doses (0·2 mg and 0·02 mg per kg bodyweight) were less consistently effective. However, infusion of the drug resulted in persistent, usually profound hypotension. We conclude that treatment of intestinal ischaemia by infusion of phentolamine into the superior mesenteric artery is unsafe.