Misumi Y, Oda K, Ikehara Y
J Biochem. 1986 Aug;100(2):433-8. doi: 10.1093/oxfordjournals.jbchem.a121731.
We have examined the effect of colchicine on the induction of alkaline phosphatase and its transport to the cell surface in a primary culture of rat hepatocytes. When freshly isolated hepatocytes were subjected to primary culture, alkaline phosphatase activity increased linearly starting at 6 h and reached a maximum level (about 10 times the initial activity) at 24 h after seeding. Radioimmunoassay with 125I-(anti-alkaline phosphatase)-IgG confirmed that the increase in enzyme activity was due to the increased amount of enzyme protein. The presence of colchicine in the culture medium (10-50 microM) did not cause an additive effect on the enzyme induction, in contrast to the previous results obtained in in vivo experiments (Ikehara, Y. et al. (1978) J. Biochem. 84, 1335-1338; Oda, K. & Ikehara, Y. (1981) Biochim. Biophys. Acta 640, 398-408). However, translocation of the induced enzyme to the cell surface was inhibited by colchicine in a dose-dependent manner. These results suggest that the enzyme induction by colchicine observed in vivo might not be due to its direct effect on hepatocytes, and that microtubules are involved in intracellular transport of the newly synthesized membrane protein.
我们研究了秋水仙碱对原代培养的大鼠肝细胞中碱性磷酸酶诱导及其向细胞表面转运的影响。当新鲜分离的肝细胞进行原代培养时，碱性磷酸酶活性从6小时开始呈线性增加，并在接种后24小时达到最高水平（约为初始活性的10倍）。用125I -（抗碱性磷酸酶）- IgG进行放射免疫测定证实，酶活性的增加是由于酶蛋白量的增加。与之前在体内实验中得到的结果相反（池原洋等人，（1978年）《生物化学杂志》84卷，1335 - 1338页；小田健和池原洋，（1981年）《生物化学与生物物理学报》640卷，398 - 408页），培养基中存在秋水仙碱（10 - 50微摩尔）对酶的诱导没有产生累加效应。然而，秋水仙碱以剂量依赖的方式抑制了诱导酶向细胞表面的转运。这些结果表明，体内观察到的秋水仙碱对酶的诱导作用可能不是由于其对肝细胞的直接作用，并且微管参与了新合成膜蛋白的细胞内转运。
