Prostaglandin E1 enhances hepatic portal venous flow by dilating the portal vascular bed in 70% hepatectomized dog

Abstract

The effects of portal, hepatic arterial and femoral venous administration of prostaglandin E1 (PGE) on portal venous flow (PVF) and hepatic arterial flow HAF were examined before and after 70% hepatectomy in anesthetized dogs. In the hepatectomized condition, portal venous administration of PGE (0.5 microgram/kg/min) caused an increase in PVF without any change in systemic arterial pressure (SAP). HAF was unchanged following the injection. The portal effect of PGE on PVF was dose-dependent, and a reduction in portal venous resistance was seen. However, the same dose of PGE failed to change PVF under intact liver conditions. Hepatic arterial administration of PGE (0.5 microgram/kg/min) brought no significant change in PVF or HAF, with or without hepatectomy. Femoral venous administration of PGE (0.5 micrograms/kg/min) produced an increase in PVF concomitant with a significant decrease in SAP. HAF showed no change after the injection. A decrease in PVR was seen only in the hepatectomized condition. It is concluded that PGE is potent in increasing PVF in the hepatectomized condition, and the portal vasculature is involved as the site of action.

The Role of Prostaglandins in Liver Ischemia-Reperfusion Injury

“…Those results in rats were consistent with studies that showed the effect of PGE 1 on hepatic IRI [174] followed by partial hepatectomy in dogs [175] with noncirrhotic livers.…”

“…PGE 1 significantly improved portal venous flow (PVF) and peripheral liver tissue blood flow (TBF) after reperfusion [177]. A similar effect was also observed in some other studies which showed on IR injury [174] and partial hepatectomy [175] individually, whereas our model was a combined one of both ischemia and hepatectomy [177].…”

“…Plugging of capillaries by neutrophils activated by superoxide anion also leads to derangements in microcirculation and hence enhances parenchymal damage [101]. Studies showed that the increase of blood flow in the liver can contribute to a good prognosis in liver disease, when the liver has been injured ischemically or has been resected partially [174][175]. We have also performed a series of studies concerning the effect of PGE 1 on rat liver IR injury and observed the restoration of good flow in the postischemic liver microvasculature on a severely injured rat liver model of hepatectomy and ischemia [176].…”

The effects of intraportal administration of prostaglandin E 1 on liver ischemia and hepatectomy in rats

“…In most of the above‐mentioned and other cases, PGE 1 was administered intravenously. However, it was confirmed that intraportal administration of PGE 1 showed the greatest protective effects against hepatic warm ischemia and reperfusion injury,21 and against partial hepatectomy22 in dogs.…”

“…The protective mechanism of PGE 1 against warm ischemia reperfusion injury of the liver was primarily achieved by increasing the portal venous flow (PVF)23 as well as by reducing the production of superoxide radicals 24. Other studies reported that PGE 1 increased the PVF in dogs22 and in rats1 when the liver was partially resected. In the resected liver the PVF is increased by dilating the vascular wall in the superior mesenteric vascular bed after infusion of PGE 1 .…”