乌拉坦对小白鼠胚胎及仔鼠肝脏酶影响的观察

The Effect of Transplacental Urethan on Enzyme of the Embryonic and Infant Liver in Swiss Mice

为了解乌拉坦(氨基甲酸乙酯)通过胎盘对动物胚胎及仔鼠肝脏正常发育与功能变化的影响,我们分别给妊娠11d、13 d、15 d、17 d及19 d的Swiss种小白鼠皮下一次性注射乌拉坦1mg/g bw,用酶组化方法检查不同时期胚胎肝及新生仔鼠肝脏几种酶的变化。对葡萄糖-6-磷酸酶(G-6-Pase)、三磷酸腺苷酶(ATPase)、5’-核苷酸酶(5’-Nase)、碱性磷酸酶(AKP)、琥珀酸脱氢酶(SDH)及糖原在不同实验条件下在肝内分布及质与量的变化进行了比较观察。结果发现在不同妊娠时期,这种化合物对胚胎及生后仔鼠肝脏酶活性均有明显影响。而且在给药后第3天这5种酶均有明显改变,尤以肝细胞酶形成期接受致癌剂后改变更明显。有意义的是G-6-Pase、ATPase、5′-Nase、ALP及糖原呈现规律性变化。可能反映了这类致癌(畸)性化合物在诱发动物产生形态学明显的肿瘤或畸形之前,肝细胞内某些酶的生成与正常调控已先有改变。

In order to understand the effect of urethan through the placental barrier on the normal development and functional changes of the animal embryonic liver,a single S. C. 10% urethan(lmg/g body weight)was given to pregnant Swiss mice on the gestational day 11,13,15,17,and 19 respectively. An enzymehistochemical expressions of the liver were examined at the different periods of embryonic and infant hepatic tissues. The distribution and contents of glucose-6-phosphatase(G-6-Pase),adenosine triphosphatase (ATPase),5'-nucleotidase (5'-Nase), alkaline phosphatase(AKP),succinate dehydrogenase (SDH),and glucogen in the liver cells were compared with the control group in various conditions. The results showed that in different periods urethan could penetrate through the placental barrier to effect the normal enzyme patterns of the developing liver significantly. We found that the expressions of several enzymes (e. g. G-6-Pase, ATPase, 5' -Nase, AKP) significantly delayed in time as comparing with the controlled animals. Probably these changes, induced by transplacental urethan, may reflect a critical damage of DNA in primordial cells and consequently express sever interference concerning the gene-regulation of some enzyme processings, both in qualitation and quantitation charactristics,before realized a tumor or malformation morphologically.