Glassmeier G, Strübing C, Riecken E O, Buhr H, Neuhaus P, Ahnert-Hilger G, Wiedenmann B, Scherübl H
Abteilung für Innere Medizin mit Schwerpunkt Gastroenterologie, Universitätsklinikum Benjamin Franklin, Freie Universität Berlin, Germany.
Gastroenterology. 1997 Jul;113(1):90-100. doi: 10.1016/s0016-5085(97)70084-2.
BACKGROUND & AIMS: Because of their diffuse distribution, neuroendocrine cells of the gut have not been isolated successfully for electrophysiological characterization. We therefore established primary cell cultures from surgically resected human carcinoids and investigated them electrophysiologically.
The neuroendocrine identity of the isolated gut tumor cells was determined immunocytochemically. The electrophysiological properties of the cells were studied by the patch-clamp technique.
The primary cell cultures expressed neurofilament proteins, cytokeratins, and key proteins of the secretion machinery. Spontaneous action potentials were observed in most cells. Using the whole-cell mode of the patch-clamp technique, tetrodotoxin-sensitive voltage-gated sodium currents as well as voltage-gated calcium currents were identified. Calcium channel currents were carried mainly by dihydropyridine-sensitive, L-type calcium channels. The L-type calcium channel currents were also partially blocked by the omega-conotoxins GVIA and MVIIC. Moreover, omega-agatoxin IVA reversibly reduced a component of the calcium channel currents, indicating that neuroendocrine gut tumor cells express different types of voltage-gated calcium channels. In addition, somatostatin was found to inhibit partially the voltage-dependent calcium channel currents and thus calcium-dependent hormone release.
Carcinoid cells of the human gut are electrically excitable cells. They express voltage-dependent sodium and calcium channels as well as somatostatin receptors.
由于肠道神经内分泌细胞分布弥散，尚未成功分离用于电生理特性研究。因此，我们从手术切除的人类类癌组织中建立了原代细胞培养物，并对其进行电生理研究。
通过免疫细胞化学方法确定分离的肠道肿瘤细胞的神经内分泌特性。采用膜片钳技术研究细胞的电生理特性。
原代细胞培养物表达神经丝蛋白、细胞角蛋白和分泌机制的关键蛋白。在大多数细胞中观察到自发动作电位。采用膜片钳技术的全细胞模式，鉴定出河豚毒素敏感的电压门控钠电流以及电压门控钙电流。钙通道电流主要由二氢吡啶敏感的L型钙通道介导。L型钙通道电流也被ω-芋螺毒素GVIA和MVIIC部分阻断。此外，ω-阿加毒素IVA可逆地降低了钙通道电流的一个成分，表明神经内分泌肠道肿瘤细胞表达不同类型的电压门控钙通道。另外，发现生长抑素可部分抑制电压依赖性钙通道电流，从而抑制钙依赖性激素释放。
人类肠道类癌细胞是电兴奋性细胞。它们表达电压依赖性钠通道和钙通道以及生长抑素受体。
