Physiological and molecular biological studies on the pathogenesis of impaired insulin secretion in diabetes mellitus.

糖尿病胰岛素分泌受损发病机制的生理和分子生物学研究。

• 批准号: 07671128
• 负责人: ISHIDA Hitoshi
• 金额: $ 1.47万
• 依托单位: KYOTO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07671128/
• 关键词: Diabetes mellitus; Pancreatic beta-cells; Insulin secretion; Patch-clamp technique; ATP-sensitive K^+ channels; Voltage-dependent Ca^<2+> channels; Intracellular Ca^<2+>; パッチクランプ法; 細胞内カルシウム濃度

As one of the major characteristics in pathophysiological aspects in noninsulin-dependent diabetes mellitus (NIDDM), the selective impairment of glucose-induced insulin secretion has been well known. On the other hand, the insulin secretory capacity is rather enhanced in response to the stimuli other than glucose. We, therefore, investigated the activity of voltage-dependent Ca^<2+> channel (VDCC) directly using the patch-clamp technique, which has a very important role on the regulation of intracellular Ca^<2+> levels. Using single beta-cells obtained by the dispersion of pancreatic islets of GK rats with genetically NIDDM,the L-and T-types of Ca^<2+> channel currents were recorded by whole cell recording. In addition, in order to investigate the intracellular mechanisms for modulating VDCC activities throuph glucose metabolism without mediating the K_<ATP> channel closure, the perforated patch using nystatin method was also utilized. Both of L-and T-type VDCC activities were found to be significautly enhanced after the membr anedepolarization in GK beta-cells when compared to the controls. In control beta-cells, the VDCC activities were more augmented after glucose loading in perforated patches. However, such an augmentation was not to be found in GK beta-cells. These phenomena seem to be closely related to the glucose selectivity of the impairment of insulin secretory capacity found in NIDDM beta cells of GK rats.

作为非胰岛素依赖型糖尿病（NIDDM）的主要病理生理特征之一，葡萄糖诱导的胰岛素分泌的选择性损害已被广泛了解。另一方面，胰岛素分泌能力响应于葡萄糖以外的刺激而增强。因此，我们采用膜片钳技术直接研究了电压依赖性Ca^2+通道（VDCC）的活性，它在细胞内Ca^2+水平的调节中起着非常重要的作用。用分离的GK大鼠胰岛β细胞，用全细胞记录法记录L型和T型Ca^<2+>通道电流。此外，为了研究在不介导K通道关闭的情况下调节葡萄糖代谢过程中VDCC活性的细胞内机制<ATP>，我们还利用了制霉菌素穿孔膜片法。GK β细胞膜去极化后L型和T型VDCC活性均明显增强。在对照β-细胞中，VDCC活性在穿孔补片中葡萄糖负荷后更增强。然而，在GK β细胞中未发现这种增加。这些现象似乎与GK大鼠的NIDDM β细胞中发现的胰岛素分泌能力受损的葡萄糖选择性密切相关。

项目成果

K. Masuda, et al.: "Effect of Troglitazone (CS-045) on insulin secretion in isolated rat pancreatic islets and HIT cells : an insulinotropic mechanism distinct from glibenclamide." Diabetologia. 38 (1). 24-30 (1995)

K. Masuda 等人：“曲格列酮 (CS-045) 对离体大鼠胰岛和 HIT 细胞胰岛素分泌的影响：与格列本脲不同的促胰岛素机制。”

N.Inagaki,et al.: "Expression and role of ionotropic glutamate receptors in pancreatic islet cells." FASEB J. 9(5). 686-691 (1995)

N.Inagaki 等人：“胰岛细胞中离子型谷氨酸受体的表达和作用。”

N. Inagaki, et al.: "Expression and role of intotropic glutamate receptors in pancreatic islet cells." FASEB J. 9 (5). 686-691 (1995)

N. Inagaki 等人：“胰岛细胞中内向性谷氨酸受体的表达和作用。”

A.Ishida-Takahashi, et al.: "Block of pancreatic ATP-sensitive K^+ channels and insulinotropic action by the antiarrhythnic agent cibenzoline." Br J Pharmacol. 117. 1749-1755 (1996)

A.Ishida-Takahashi 等人：“抗心律不齐药西苯唑啉阻断胰腺 ATP 敏感 K + 通道和促胰岛素作用。”

Y. Okamoto, H. Ishida et al.: "Hyperresponse in calcium-induced insulin release from electrically permeabilized pancreatic islets of eiabetic GK rats and its defective augmentation by glucose." Diabetologia. 38(7). 772-778 (1995)

Y. Okamoto、H. Ishida 等人：“糖尿病 GK 大鼠的电透化胰岛中钙诱导的胰岛素释放的超反应及其通过葡萄糖的缺陷增强。”