Effect of prostaglandin E1 on blood flow in normal and ischemic canine hindlimbs.

Prostaglandin E1 (PGE1) is a potent vasodilator that will increase peripheral blood flow. After infusion of PGE1, little is known about the distribution of flow between skin and muscle or the effect of PGE1 on an ischemic leg. We infused intra-arterially PGE1 (5 ng/kg/min) into normal and ischemic canine hindlimbs. Radioactive microspheres were used to measure nutrient flow to skin and muscle and flow shunted through arteriovenous connections. Intra-arterial PGE1 caused significant increases in skin blood flow in both normal and ischemic hindlimbs. Shunted flow did not increase. Muscle flow increased in normal canine hindlimbs, but this increase was prevented by femoral artery ligation. We conclude that PGE1 increases absolute nutrient flow rather than opening arteriovenous shunts in the canine hindlimb. Skin flow is most sensitive to prostaglandin infusion. Muscle flow is increased in normal but not ischemic limbs. PGE1 may be useful in situations where vasospasm is a prominent feature. The role of PGE1 in atherosclerotic ischemic disease remains unclear.