我们用光镜和电镜观察了5′—核苷酸酶和硷性磷酸酶在二乙基亚硝胺诱发SD大鼠肝癌细胞中的定位,结果发现这两种酶是定位在正常鼠肝细胞毛细胆管微绒毛区和SD大鼠肝癌癌细胞毛细胆管微绒毛区,而且后者(图3、4、5)比前者(图1、2)丰富得多。提示肝癌患者血清中上述两种酶显著增高,可能系因癌变而使酶经毛细胆管附近的相邻两个细胞缝隙连接而进入血液循环。 We observed the localization of 5′-nucleotidase and alkaline phosphatase in diethylnitrosamine induced SD rat hepatoma cells by light and electron microscopy. We found that these two enzymes were localized in normal mouse liver cells. Bile duct microvilli area and SD rat hepatocarcinoma cells are bile duct microvilli areas, and the latter (Figs. 3, 4 and 5) are much richer than the former (Figs. 1 and 2). It is suggested that the above two enzymes in the serum of patients with liver cancer are significantly increased, which may be due to cancerous changes and the enzymes enter the blood circulation through the gap between two adjacent cells near the capillary bile duct.