Valverde I, Sener A, Lebrun P, Herchuelz A, Malaisse W J
Endocrinology. 1981 Apr;108(4):1305-12. doi: 10.1210/endo-108-4-1305.
Pancreatic islets contain calmodulin. This protein activates adenylate cyclase in a subcellular fraction of rat islets in a calcium-dependent fashion. The Km for calmodulin was close to 0.1 microM, well below the concentration of endogenous calmodulin. Trifluoperazine and the trifluoromethylphenothiazine derivative of domperidone inhibited glucose-stimulated insulin release without affecting glucose oxidation by the islets. When insulin release was inhibited by 30% or more, this inhibition coincided with a reduction in the 45Ca net uptake by the islets. Both drugs suppressed the increment in adenylate cyclase activity evoked by calmodulin in a particulate fraction derived from the islets. However, the drugs also decreased basal and NaF-stimulated adenylate cyclase activities. Within limits, these data are compatible with the participation of endogenous calmodulin in the normal process of insulin release.
胰岛含有钙调蛋白。这种蛋白质以钙依赖的方式激活大鼠胰岛亚细胞组分中的腺苷酸环化酶。钙调蛋白的米氏常数接近0.1微摩尔，远低于内源性钙调蛋白的浓度。三氟拉嗪和多潘立酮的三氟甲基吩噻嗪衍生物抑制葡萄糖刺激的胰岛素释放，而不影响胰岛的葡萄糖氧化。当胰岛素释放被抑制30%或更多时，这种抑制与胰岛45Ca净摄取的减少相吻合。两种药物均抑制钙调蛋白在源自胰岛的微粒体组分中引起的腺苷酸环化酶活性的增加。然而，这些药物也降低了基础和氟化钠刺激的腺苷酸环化酶活性。在一定范围内，这些数据与内源性钙调蛋白参与胰岛素释放的正常过程相一致。
