Endothelin in liver cell injury and regeneration after 70% hepatectomy with portal ischemia.

Hepatic ischemia-reperfusion (IR) injury caused by portal vein clamping is a common problem in hepatobiliary surgery. Endothelin (ET) is a potent vasoconstrictor and is associated with IR injury. This study evaluated the effect of ET on liver cell injury and hepatic regeneration after hepatectomy with IR. The portal veins of rats were clamped for 20 min, then unclamped and a 70% partial hepatectomy was performed. TAK-044 (TAK), the nonselective ETA/ETB receptor antagonist, was administered s.c. 30 min before laparotomy [TAK(+)]. Portal blood ET-1, GOT levels, hepatic blood flow, histologic change, DNA synthesis of hepatocytes, and the relationship of Ito cells and perisinusoidal cells were evaluated. ET-1 concentration increased after IR and was significantly higher in the TAK(+) group owing to the blockade of ET receptors. Increased GOT levels and sinusoidal congestion were reduced, but DNA synthesis of hepatocytes and hepatic blood flow did not change in the TAK(+) group. Changes in desmin staining showed that Ito cells might be related to IR injury. In conclusion, ET-1 was associated with IR injury and TAK-044 reduced but did not affect hepatocyte DNA synthesis after partial hepatectomy.