Estacion M, Mordan L J
Molecular Oncology Program, Cancer Research Center of Hawaii, Honolulu.
Cell Calcium. 1993 Feb;14(2):161-71. doi: 10.1016/0143-4160(93)90085-k.
Platelet derived growth factor (PDGF) mobilizes multiple calcium pools in the C3H 10T1/2 mouse fibroblast, including a sustained influx of extracellular calcium. We have used the whole cell patch-clamp technique to directly test for a role of plasma membrane calcium channels in this influx. Whole-cell patch-clamp recordings revealed a voltage-gated calcium channel with gating properties consistent with a 'T-type' designation. This phenotype of the C3H 10T1/2 fibroblasts was dependent upon the cell density in culture. The fraction of cells expressing calcium channels was low (< 10%) in subconfluent culture but rose to approximately 50% as the cells established a confluent monolayer. The magnitude of the PDGF-stimulated sustained calcium influx component measured using Fura-2 increased in parallel with the expression of calcium current. We interpret these results to support the hypothesis that T-type voltage-gated calcium channels contribute to the PDGF-stimulated intracellular calcium signals in these cells.
血小板衍生生长因子（PDGF）可动员C3H 10T1/2小鼠成纤维细胞中的多个钙池，包括细胞外钙的持续内流。我们使用全细胞膜片钳技术直接检测质膜钙通道在这种内流中的作用。全细胞膜片钳记录显示了一种电压门控钙通道，其门控特性与“T型”通道一致。C3H 10T1/2成纤维细胞的这种表型取决于培养中的细胞密度。在亚汇合培养中，表达钙通道的细胞比例较低（<10%），但随着细胞形成汇合单层，这一比例上升至约50%。使用Fura-2测量的PDGF刺激的持续钙内流成分的大小与钙电流的表达平行增加。我们解释这些结果以支持以下假设：T型电压门控钙通道有助于这些细胞中PDGF刺激的细胞内钙信号。
