The influence of portal vein occlusion on liver mitochondria in rats after releasing biliary obstruction.

Biliary obstruction often follows advanced cancers of the biliary system, such as pancreas cancer, which requires a resection of the involved portion of the portal vein. To improve the patient's state of obstructive jaundice, bile drainage should be performed before the operation. Temporaryocclusion of the portal vein is inevitable for a resection and reconstruction of the portal vein, and its detrimental influence on the liver remains to be resolved. In this study, the effect of portal vein occlusion on rat liver mitochondria was investigated after releasing biliary obstruction. The common bile duct of the male Donryu rat was ligated and, after a certain duration, was recanalized to allow for external bile drainage. Then the portal blood flow was blocked for either IS or 30-rnin. At the end of the experiment, the following parameters were examined: the respiratory functions and ultrastructures of liver mitochondria, and the serum levels of hepatic enzymes. A significant reduction of the respiratory functions was observed in the 30-min occlusion group regardless of the length of the biliary obstruction period; also the ultrastructures of the liver mitochondria showed severe changes associated with increased s-GPT and m-GOT. These results indicate that IS-min occlusion of the portal vein after releasing biliary obstruction has a negligible effect on the liver functions, but 30-min occlusion induces dysfunction of liver cells. Therefore, additional countermeasures to clear such liver dysfunction should be employed in biliary tract surgery, provided that a prolonged portal vein occlusion is inevitable.