The reaction to thromboxane thromboxane A_2 in smooth muscle cells

平滑肌细胞对血栓素血栓素A_2的反应

• 批准号: 04670568
• 负责人: TAKAHARA Kazuo
• 金额: $ 1.47万
• 依托单位: University of Occupational and Environmental Health, school of Medical Technology (1994)University of Occupational and Environmental Health, Japan (1992-1993)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1992
• 资助国家: 日本
• 起止时间: 1992 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04670568/
• 关键词: thromboxane A_2; smooth muscle cell; platelets; calcium; 平滑筋細胞; 細胞内Ca^<2+>反応

To study the reaction thromboxane A_2 in smooth muscle cells, we studied the reaction to thromboxane A_2 in platelets. The regulation of extracelluler Ca^<2+> entry into platelets was studied using nisoldipine. Nisoldipine or vehicle was added to fura2-loaded-platelets in the presence of CaCl_2 and an activator, a thromboxane A_2 agonist (U46619) or thrombin, was also added. In the other experiments, CaCl_2 was added after the activator to platelet samples containing EDTA.The U46619-evoked increase of [Ca^<2+>] i was suppressed by nisoldipine, but the thrombin-evoked [Ca^<2+>] i increase was not suppressed. When CaCl_2 was added to Ca^<2+>-free medium after platelet the activation, the increase of [Ca^<2+>] i due to U46619 was suppressed by nisoldipine, but not that due to thrombin. In addition, nisoldipine significantly suppressed platelet aggregation and secretion induced by U46619, but had no effect on the response to thrombin. These data suggest that Ca^<2+> entry through the platelet membrane is regulated by two or more types of Ca^<2+> channeles, including thromboxane A_2-activated and thrombin-activated channels. Only the former type of channel was blocked by nisoldipine.

为了研究血栓素A_2在平滑肌细胞中的反应，我们研究了血小板对血栓素A_2的反应。用尼索地平研究了细胞外Ca^2+进入血小板的调节。在CaCl_2存在下，将尼索地平或赋形剂加入到载有呋喃的血小板中，并加入激活剂血栓素A_2激动剂（U46619）或凝血酶。在另一实验中，在含EDTA的血小板样品中加入CaCl_2后，尼索地平可抑制U46619引起的[Ca^<2+] i升高，但对凝血酶引起的[Ca^<2+] i升高无抑制作用。在血小板活化后的无Ca^2+培养液中加入CaCl_2，尼索地平可抑制U46619引起的[Ca^2+] i升高，但对凝血酶引起的[Ca^2+] i升高无影响。此外，尼索地平显著抑制U46619诱导的血小板聚集和分泌，但对凝血酶的反应没有影响。这些结果表明，血小板膜Ca^2+进入受两种或多种Ca^2+通道的调节，包括血栓素A_2激活的和凝血酶激活的Ca ^2+通道。尼索地平仅阻断前一种通道。

项目成果

A.Fujinishi,K.Takahara,Y.Nakashima,A.Kuroiwa,et al: "Nisoldipine may differentiate the calcium channels in platelets activated by thromboxane A_2 and thrombin" Circulation. 90. I-302 (1994)

A.Fujinishi，K.Takahara，Y.Nakashima，A.Kuroiwa，et al：“尼索地平可以区分由血栓素A_2和凝血酶激活的血小板中的钙通道”循环。

A.Fujimishi,K.Takahara,Y.Nakashima,A.Kuroiwa,et al: "Nisoldipine may differentiate the calcium channels in platelets activated by thromboxane A_2 and thrombin" Circulation. 90. I-302 (1994)

A.Fujimishi，K.Takahara，Y.Nakashima，A.Kuroiwa，et al：“尼索地平可以区分由血栓素A_2和凝血酶激活的血小板中的钙通道”循环。

A.Fujinishi, K.Takahara Y.Nakashima, A.Kuroiwa, et al: "Nisoldipine may differentiate the calcium channels in platelets activated by thromboxane thromboxane A_2 and thrombin" Circulation. 90. 1-302 (1994)

A.Fujinishi、K.Takahara Y.Nakashima、A.Kuroiwa 等人：“尼索地平可以区分由血栓素血栓素 A_2 和凝血酶激活的血小板中的钙通道”循环。