Cytoprotective effect of prostaglandin I2 on ischemia-induced hepatic cell injury

The protective effect of prostaglandin I2 (PGI2) on ischemia-induced liver cell injury was investigated during 60-min, 75-min, and 90-min liver ischemia. Vehicle-treated rats tolerated the 75-min hepatic ischemia poorly. Only 25% of the rats in this group survived more than 7 days. However, the survival rate of PGI2-treated rats (350 ng/kg/min) significantly improved to 67%. Liver cell organelles were well-preserved by the PGI2 treatment. Adenosine triphosphate levels in the liver of the PGI2-treated rats were significantly higher than those of vehicle-treated rats at 60 min of reoxygenation following 75-min ischemia. Cyclic 3'-5' adenosine monophosphate levels markedly increased during 60-min PGI2 infusion. Cyclic 3'-5' guanosine monophosphate levels also significantly increased during the PGI2 infusion and were still higher than those of vehicle-treated rats at the end of the 75-min ischemia. Although the exact cytoprotective mechanism of PGI2 at the cellular level is still unclear, our results demonstrate that elevated ATP and cyclic nucleotides levels play an important role in liver cell preservation during ischemia.