Significance of prednisolone administration for hepatic mitochondrial function of the rat with biliary obstruction

Mitochondrial respiratory function of the liver is disturbed in biliary obstruction, especially in that caused by tumours in the hepatobiliary system. This study aimed to clarify whether a glucocorticoid, prednisolone succinate, is effective to improve the reduced mitochondrial function of the rat liver in obstructive jaundice. Five doses of 5 mg/kg or 25 mg/kg prednisolone succinate were administered at 5 consecutive days to the rats after 1, 3 or 6 weeks of biliary obstruction and to the rats without obstruction, and the hepatic mitochondrial function and contents of cytochromes of these rats were investigated. With 25 mg/kg prednisolone, hepatic mitochondrial function was improved in rats with biliary obstruction of 3- or 6-weeks duration as compared with the prednisolone-untreated group. Compensatory increase or recuperation of the once decreased cytochrome A(+a3) and/or turnover number of phosphorylation was also observed in 25 mg/kg group. Hepatic mitochondrial function of obstruction-free animals was rather impaired by treatment with 25 mg/kg prednisolone. In 5 mg/kg group, above mentioned effects were scarcely observed. It was concluded that the hepatic mitochondrial function in animals with prolonged biliary obstruction, as same as in animals with short-term obstruction, can be improved by the administration of adequately large amounts of prednisolone.