Prior Administration of Prostaglandin E_1 Enhances the Indocyanine Green Disappearance Rate Associated with Liver Ischemia in Rats

The plasma disappearance rate of indocyanine green (ICG-K) under liver ischemia was examined with or without prostaglandin E_1 (PGE1) administration in anesthetized rats. Liver ischemia was induced for 10 min by clamping the portal vein and the hepatic artery. PGE1 40 μg/kg was introduced into the portal vein or into the jugular vein immediately after the liver vascular clamping. Saline was used as the control. ICG-K was estimated for 180 min after the ischemia, and ICG-K values 60,120 and 180 min were higher in the portal PGE1 rats than in the control rats. The ICG-K response was blocked by a selective PGE1 receptor antagonist. Otherwise, no difference in ICG-K was seen between jugular PGE1 rats and the control. These results suggest that PGE1 injection under liver circulatory occlusion is specifically capable of diminishing ischemic damage to the hepatocytes, and such an effect of PGE1 is evident when administered into the portal vein rather than into the systemic circulation.