小鼠肝匀浆对脑GABA降解的抑制作用

THE IN VITRO INHIBITION OF CEREBRAL GABA DEGRADATION BY THE LIVER HOMOGENATE SUPERNATANT OF MICE

用偶联酶学荧光分光光度法测定脑GABA-T活性,在小鼠肝昏迷模型中证实了Ferenci等报道的肝昏迷兔血清能抑制脑GABA降解的实验结果,并首次报道了正常及肝昏迷小鼠LHS对脑GABA降解也有抑制作用。说明正常肝细胞中存在有对脑GABA降解有抑制作用的物质。它是肝脏特有的或主要存在于肝脏。对GABA降解抑制物参与肝昏迷发病机制的可能性进行了讨论。

The cerebral GABA-T activity of mice was determined by the modified coupled-enzyme spectroflourimctry, and the method was proved stable and feasible. The cerebral GABA degradation of mice in vitro was inhibited by the sera from the mice with hepatic coma induced by galactosamine. The supernatant of liver homogenate of both control and hepatic coma groups can inhibit the cerebral GABA degradation too. The inhibitory capacity is proportional to the volume of LHS added in certain conditions, and reaches a maximum inhibitory rate of 80%. The inhibition can not be relieved by pyridoxal phosphate.The inhibitory effector of cerebral GABA degradation has been regarded as liver specific or mainly presented in the liver since no appreciable inhibition was found after the addition of the supernaiants of kidney, heart, lung and spleen homogenates. The possible contribution of GABA degradation inhibition by LHS to the pathogenesis of hepatic encephalopathy has also been discussed