Evidence that estrogen receptors play a limited role in mediating enhanced recovery of bile flow in female rats in the acute phase of liver ischemia reperfusion injury

Introduction. Female patients exhibit better survival and less hepatic damage from ischemia reperfusion (IR) injury following surgery. However, the effects of sex and estrogens on liver function in the acute phase of IR are not well understood. Objective. The aim was to investigate this question. Material and methods. A rat model of segmental hepatic ischemia was employed. Rats were pre-treated with the estrogen receptor antagonist ICI182,780 and/or the estrogen receptor agonist 17β-estradiol. Bile flow, blood concentrations of bilirubin and liver enzymes were measured, and liver histology was assessed. Results. Bile flow recovery immediately after the initiation of reperfusion was faster in females than in males. ICI182,780 reduced the rate of bile flow recovery in females but this reduction was not reversed by co-administration of 17 β-estradiol. In males, 17 β-estradiol alone did not enhance bile flow recovery. The changes in bile flow recovery observed under a given condition were correlated with small changes in blood liver enzymes and liver histology. Conclusions. Sex has a significant influence on the early recovery of liver function in the acute phase of IR injury. However, in female rats estrogen receptors play only a limited role in mediating enhanced recovery of liver function.