Altered expression of heme oxygenase-1 in the livers and blood carbon monoxide level of rats with obstructive jaundice

Objective To investigate the effect of altered hepatic heme oxygenase--1 (HO--1) ex- pression and blood carbon monoxide (CO) level on hepatic function in obstructive jaundice. Methods Forty-eight Wister rats were divided randomly into control group (CG), bile duct ligation 7--day group (7 d), bile duct ligation 14--day group (14 d) and bile duct ligation 21--day group (21 d). Immunohisto- chemistry and double--wavelength spectrophotometer were employed to detect the expression of HO-1 pro- tein in hepatocytes and the blood CO levels in the hepatic vein, the portal vein and the inferior vena cava. Results HO-1 was expressed only in kupffer cells of the liver in CG group. But the rats with jaundice, HO-1 was expressed in kupffer cells as well as parenchymal liver cells, and the HO-1 expression levels of the parenchymal liver cells in 14 d group and 21 d group were increased more significantly than that in 7 d group (P 0. 05, P 0. 01). There was a significant increase of the CO level of hepatic vein in the rats with jaundice in contrast to CG group (P 0. 05, P 0. 01). As compared with CG group, the CO level of portal vein in 14 d group was significantly increased (P 0. 05). The CO level of hepatic vein was higher than that of portal vein after ligating common bile duct (P 0. 01). There was a significant posi- tive correlation between the CO levels of hepatic vein and altered HO--1 expression of parenchymal liver cells in jaundiced rats (P 0. 01). Conclusion Up--regulation of HO-1 expression of parenchymal liver cells in obstructive jaundice and following high levels of hepatic CO could increase hepatic blood flow, thus leading to the alleviation of hepatic dysfunction in obstructive jaundice.