褪黑素对肝脏低温保存损伤的保护作用

目的　探讨MT对肝脏冷保存有无保护作用及其机制。方法　收集SD♂大鼠肝脏灌洗液 ,对反映肝细胞功能的ALT、AST、LDH和反映内皮细胞功能的HA、ET1和反映细胞氧化性损伤的MDA、SOD及光镜和电镜下肝组织形态学变化进行分析 ,同时设立UW液 +褪黑素 (Mel)不同时间及不同Mel浓度冷保存组 ,比较分析Mel的冷保存保护作用及不同时间及不同浓度的Mel对肝脏冷保存保护作用的影响。结果　①UW冷保存随着时间延长肝细胞和内皮细胞损害逐渐加重。②Mel对供肝冷保存损伤有保护作用。其保护机制可能与Mel强大的抗氧化损伤作用有关。③Mel 1× 10 - 5 mol·L- 1、1× 10 - 7mol·L- 1浓度时其保护作用优于Mel 1× 10 - 9mol·L- 1,而Mel 1× 10 - 5 mol·L- 1、1× 10 - 7mol·L- 1浓度间没有差异。提示Mel对肝脏冷保存损伤保护存在着浓度效应 ,随着时间延长Mel对肝脏冷保存损伤保护作用逐渐减弱 ,但优于单纯UW液冷保存组。结论　UW冷保存液对肝脏的冷保存随时间延长保护作用逐渐减弱 ,Mel液对肝脏冷保存损伤有保护作用 ,其机制与Mel的抗氧化损伤作用有关

Protection of melatonin against liver injuries induced by low-tempreture preservation

AIMTo study whether Mel has protective role in liver c old preservation and its mechanism. METHODSTo study the role of Mel at the different concentration and time in liver cold preservation, we colle cted liver washing liquid and liver tissue from male SD rats. We analysed ALT, AST, LDH, HA, ET 1, MDA and SOD to see the function of liver cell and sinusoida l lining cell and mechanism of cell injury. At the same time, we studied the eff ects of Mel at different concentration and different time on liver cold preserva tion. RESULTS① The damage to liver function and change of its histology was aggravated with the prolongation of UW co ld preservation time, and injury of the sinusoidal lining cell was also aggravated gr adually. ② Indexes of the liver function and the sinusoidal lining cell functio n in the Mel solution cold preservation group were lower than that in the UW sol ution cold preservation group. These suggest protective role of Mel against live r injury caused by cold preservation. Its mechanism may be related to powerful a nti-oxidative effect of Mel. ③ The protective effect of Mel at 1×10 -5 m ol·L -1 ,1×10 -7 mol·L -1 was better than that of Mel at 1×10 -9 mol·L -1 . We found no obvious difference between the protection of Mel 1×10 -5 mol·L -1 and 1×10 -7 mol·L -1 indicati ng a concentration-effect relationship. CONCLUSIONProtective ef fect of UW solution used in clinic weakens gradually as cold preservation time increases. Mel solution has protective effect on liver cold preservation injury and is better than the simple UW solution. Its mechanism is related to anti-oxi dative effect of Mel.