Nakamura J
Institute for Clinical Medicine, University of Tsukuba, Ibaraki-ken, Japan.
Alcohol Clin Exp Res. 1996 Apr;20(2):302-6. doi: 10.1111/j.1530-0277.1996.tb01643.x.
Adenylyl cyclase activity was determined in membranes from wild-type S49 murine lymphoma cells that had been exposed to ethanol for 4 hr. Mn-, NaF-, and forskolin-stimulated adenylyl cyclase activities of cells-pretreated with cycloheximide, puromycin, or serum deprivation-were significantly decreased by treatment with 50 mM of ethanol. As demonstrated for Mn-stimulated activity, the decrease was dose-dependent on ethanol and was temporal; a normal activity recovered after 16-24 hr treatment, even in the presence of cycloheximide and ethanol. Studies with a cell-free membrane system of S49 cells revealed a similar activity decrease after treatment of the membranes with ethanol. In contrast, cells treated with 50 mM of ethanol in a regular culture condition showed no decrease in adenylyl cyclase activity over 24 hr. These results indicate that ethanol regulation of adenylyl cyclase activity in S49 cells depends on reduced or impaired protein synthesis.
测定了暴露于乙醇4小时的野生型S49鼠淋巴瘤细胞膜中的腺苷酸环化酶活性。用环己酰亚胺、嘌呤霉素预处理或血清剥夺处理后的细胞，其锰离子、氟化钠和福斯高林刺激的腺苷酸环化酶活性在用50 mM乙醇处理后显著降低。正如锰离子刺激活性所显示的那样，这种降低与乙醇呈剂量依赖性且具有时间性；即使在存在环己酰亚胺和乙醇的情况下，经过16 - 24小时处理后活性也会恢复正常。对S49细胞的无细胞膜系统进行的研究表明，用乙醇处理膜后活性也会出现类似降低。相比之下，在常规培养条件下用50 mM乙醇处理的细胞在24小时内腺苷酸环化酶活性没有降低。这些结果表明，乙醇对S49细胞中腺苷酸环化酶活性的调节取决于蛋白质合成的减少或受损。
