摘要：Isoproterenol (IPN)-stimulated activity of adenylate cyclase was enhanced in a dose-dependent manner by exposure of AH130 cells to mitomycin C (MMC). The enhancement was also observed in prostaglandin E1-, guanine nucleotide analog-, NaF-, cholera toxin- and forskolin-stimulated activities of the enzyme but not in manganese-stimulated activity. In addition, even when the cells pretreated with islet-activating protein were exposed to MMC, IPN-stimulated activity of adenylate cyclase was enhanced. Anaerobic exposure of AH130 cells to MMC somewhat inhibited IPN-stimulated activity of adenylate cyclase in contrast with aerobic exposure. Exposure of cells to adriamycin also caused enhancement of IPN-stimulated activity of adenylate cyclase but exposure to nitrogen mustard inhibited the enzyme stimulation by IPN. The enhancing effect of MMC was lost by the combined treatment with α-tocopherol. From these results, it was shown that MMC modulated the activity of adenylate cyclase, probably through alterations in membrane structure.
