INOSITOL 1,4,5-TRISPHOSPHATE- AND GUANOSINE 5'-O-(3-THIOTRIPHOSPHATE)-INDUCED CA2+ RELEASE IN CULTURED AIRWAY SMOOTH-MUSCLE
INOSITOL 1,4,5-TRISPHOSPHATE- AND GUANOSINE 5'-O-(3-THIOTRIPHOSPHATE)-INDUCED CA2+ RELEASE IN CULTURED AIRWAY SMOOTH-MUSCLE
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DOI：
10.1111/j.1476-5381.1991.tb12524.x
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发表时间：
1991-12-01
影响因子：
7.3
通讯作者：
WARD, JPT
中科院分区：
文献类型：
--
作者：
CHOPRA, LC;TWORT, CHC;WARD, JPT
1用Ca-45外排法研究1，4，5-三磷酸肌醇(InsP3)与鸟苷5‘-O-(3-硫代三磷酸)(GTP-γ-S)释放钙池的相互作用。2加入InsP3或GTP-γ-S可引起细胞内钙离子浓度依赖性释放。InsP3对钙的释放明显高于GTP-γ-S。最有效的InsP3(10-mU-M)可阻断GTP-γ-S诱导的细胞内钙释放，而100-mU-GTP-γ-S可使InsP3诱导的细胞内钙释放减少25%。经100 mU-M兰尼定处理后，GTP-γ-S不诱导细胞内钙离子释放，InsP3诱导的细胞内钙释放减少76%。4.咖啡因(50 MM)可引起细胞内钙离子缓慢释放。预先暴露于50 mM咖啡因对GTP-γ-S诱导的Ca~(2+)释放无影响，但可使InsP_3释放的Ca~(2+)减少58%。5兰尼定可阻断咖啡因诱导的Ca~(2+)释放，在Ryanodine之前加入咖啡因可使Ryanodine诱导的Ca~(2+)释放减少64.4%。6这些结果表明，气道平滑肌细胞内至少存在三个钙池。最大的库由InsP3或Ryanodine释放，另一个由高浓度InsP3或GTP-γ-S释放，第三个单独由InsP3释放。当GTP-伽马-S敏感池耗尽时，Ca~(2+)可能能够从GTP-伽马-S敏感池进入InsP3和Ryanodine敏感池。相反，钙离子不会发生相反的运动。
1 The interaction between inositol 1,4,5-trisphosphate (InsP3) and guanosine 5'-O-(3-thio triphosphate) (GTP-gamma-S) releasable calcium (Ca2+) pools was examined using Ca-45 effluxes in permeabilized cultured airway smooth muscle cells from rabbit trachea.2 Addition of InsP3 or GTP-gamma-S caused a concentration-dependent release of intracellular Ca2+. The release of Ca2+ by InsP3 was much greater than with GTP-gamma-S. Pretreatment with maximally effective InsP3 (10-mu-M) abolished the GTP-gamma-S-induced Ca2+ release, whereas pretreatment with 100-mu-M GTP-gamma-S reduced the InsP3-induced Ca2+ release by 25%.3 Ryanodine (100-mu-M), also gave a large release of intracellular Ca2+. After pretreatment with 100-mu-M ryanodine, GTP-gamma-S did not induce Ca2+ release, and InsP3-induced Ca2+ release was reduced by 76%.4 Caffeine (50 mM), produced a slow release of intracellular Ca2+. Pre-exposure to 50 mM caffeine had no effect on the GTP-gamma-S-induced Ca2+ release but reduced the InsP3 releasable Ca2+ by 58%.5 Pretreatment with ryanodine abolished the caffeine-induced Ca2+ release, and addition of caffeine before ryanodine reduced the ryanodine-induced Ca2+ release by 64.4%.6 These results suggest that there are at least three pools of Ca2+ present within airway smooth muscle cells. The largest pool is released by InsP3 or ryanodine, another is released either by a high concentration of InsP3 or on application of GTP-gamma-S, and the third by InsP3 alone. Ca2+ may be able to move from the GTP-gamma-S-sensitive pool into the InsP3- and ryanodine-sensitive pool when this becomes depleted. In contrast, the opposite movement of Ca2+ cannot occur.