Thromboxane as a possible hepatotoxic factor increased by endotoxemia in obstructive jaundice.

In a study using rats, we investigated whether liver damage induced by endotoxemia in obstructive jaundice is associated with thromboxane (TX) in order to acertain whether its vasoconstrictive and platelet aggregating properties play a role in reducing liver blood flow. The rats were divided into the following 5 groups; a control group, an endotoxin (Et) group, a bile duct ligation (BDL) group, a bile duct ligation and endotoxin (BDL + Et) group and an OKY046 (Thromboxane synthetase inhibitor) treated bile duct ligation + endotoxin (OKY-BDL + Et) group. The blood TXB2 levels in the Et, BDL and BDL + Et groups were higher than those in the control group. The liver TXB2 levels in the Et and BDL + Et groups were also higher than those in the control group. Liver phospholipids and liver blood flow decreased in the BDL + Et group, whereas in the OKY-BDL + Et group they returned close to the control group levels by decreasing the TXB2 levels in both the liver and blood to normal. These results suggest that the high level of TX in the blood and liver tissue may further aggrevate the liver during endotoxemia in obstructive jaundice by inhibiting liver blood flow.