AIM: To investigate the perioperative changes of nitric oxide (NO) and endothelin (ET), thromboxane A2 (TXA2) and prostaglandin (PGI2) during liver transplantation in end-stage liver disease patients.METHODS: Twenty-seven patients with end-stage cirrhosis undergoing liver transplantation were enrolled in this prospective study. Blood samples were obtained from superior vena at five different surgical stages.Plasma concentrations of nitrate and nitrite were determined to reflect plasma NO levels. Plasma levels of ET-1,6-keto-PGF1 alpha and thromboxane B2 (TXB2),the latter two being stable metabolites of PGI2 and TXA2 respectively, were measured.RESULTS: The NO level decreased significantly after vascular cross-clamping and increased significantly at 30 min after reperfusion. While the ET levels at 30 min after clamping and after reperfusion were significantly elevated. The ratio of NO/ET decreased significantly at 30 min after vascular cross-clamping and at the end of surgery. The PGI2 level and the TXA2 during liver transplantation were significantly higher than the baseline level, but the ratio of TXA2/PGI2 decreased significantly at 30 min after clamping.CONCLUSION: NO/ET and TXA2/PGI2 change during liver transplantation. Although the precise mechanism remains unknown, they may play a role in the pathobiology of a variety of liver transplant-relevant processes.