Takuwa N, Takuwa Y, Bollag W E, Rasmussen H
J Biol Chem. 1987 Jan 5;262(1):182-8.
Bombesin, a peptide mitogen for a variety of cell types, acts as a typical Ca2+-mobilizing hormone in Swiss 3T3 fibroblasts. At its mitogenic concentrations (1-25 nM), bombesin stimulates polyphosphoinositide turnover, i.e. breakdown of phosphatidylinositol 4,5-bisphosphate and a concomitant increase in inositol phosphates in a time- and dose-dependent manner. In particular, bombesin induces an initial transient increase in inositol 1,4,5-trisphosphate concentration, followed by an increase in the concentration of inositol 1,3,4-trisphosphate. Also, within 30 s of bombesin addition, the mass of 1,2-diacylglycerol nearly doubles and remains at this level for up to 60 min. Intracellular [Ca2+] measurements with a photoprotein, aequorin, demonstrate that bombesin stimulates a transient rise in cytosolic free Ca2+ concentration. A mobilization of Ca2+ from an intracellular pool is observed as a dose-dependent, transient increase in 45Ca2+ efflux from prelabeled cells, both in the presence and absence of extracellular Ca2+. Bombesin also induces a sustained increase in Ca2+ influx rate and stimulates 3-O-methyl-D-glucose transport across the plasma membrane. These composite results indicate that the mitogenic effect of bombesin is mediated through an activation of the Ca2+ messenger system.
蛙皮素是一种对多种细胞类型有促有丝分裂作用的肽，在瑞士3T3成纤维细胞中作为典型的钙动员激素发挥作用。在其促有丝分裂浓度（1 - 25 nM）下，蛙皮素以时间和剂量依赖性方式刺激多磷酸肌醇周转，即磷脂酰肌醇4,5 - 二磷酸的分解以及肌醇磷酸的相应增加。特别是，蛙皮素诱导肌醇1,4,5 - 三磷酸浓度最初短暂升高，随后肌醇1,3,4 - 三磷酸浓度升高。此外，添加蛙皮素后30秒内，1,2 - 二酰基甘油的量几乎翻倍，并在该水平维持长达60分钟。用发光蛋白水母发光蛋白进行的细胞内[Ca2 +]测量表明，蛙皮素刺激胞质游离Ca2 +浓度短暂升高。在有和没有细胞外Ca2 +的情况下，均观察到从细胞内池动员Ca2 +表现为预标记细胞中45Ca2 +流出的剂量依赖性短暂增加。蛙皮素还诱导Ca2 +流入速率持续增加，并刺激3 - O - 甲基 - D - 葡萄糖跨质膜转运。这些综合结果表明，蛙皮素的促有丝分裂作用是通过激活Ca2 +信使系统介导的。
