哮喘豚鼠气道平滑肌细胞内钙释放通道的变化

目的检测哮喘豚鼠气道平滑肌细胞(ASMCs)内钙释放通道功能的改变,探讨与支气管哮喘的关系,同时,寻找传代培养ASMCs的方法。方法以Flou-3/AM为细胞内钙离子示踪剂,观察ASMCs在工具药作用下细胞内钙离子浓度([Ca2+]i)的改变。结果①在ASMCs外无钙情况下,不同浓度ryanodine(5×10-5,10-4,2×10-4mol·L-1)作用于原代培养正常与哮喘ASMCs,[Ca2+]i迅速升高,哮喘组明显高于正常组(P<0·01)。10-4mol·L-1的组织胺(hista-mine)作用于原代培养的正常组与哮喘组ASMCs,[Ca2+]i升高无差异(P>0·05)。②传代培养哮喘ASMCs在10-4、2×10-4mol·L-1ryanodine作用下,[Ca2+]i迅速升高,与原代细胞比较无差异(P>0·05)。在浓度为5×10-5mol·L-1时,原代明显高于传代(P<0.01)。哮喘组传代ASMCs对10-4mol·L-1的histamine反应不明显。结论哮喘豚鼠ASMCs内钙释放通道(RyRs)功能升高,特定条件下,哮喘传代细胞仍然保持原代细胞内钙释放通道的特性。

Altered intracellular Ca2+ channel function of cultured asthmatic guinea pig airway smooth muscle cells

Aim To investigate the functional change of intracellular Ca~ 2+ channels of cultured asthmatic guinea-pig airway smooth muscle cells(ASMCs) and to comprehend its relationship with asthma. Methods [Ca~ 2+ ]_i was measured in presence of different pharmaceutical products with Flou-3/AM as a fluorescent Ca~ 2+ indicator. The cell photofluorogram was gathered by a camera interlined with an inverted fluorescence microscope. Results ① In extracellular Ca~ 2+ -free condition, different concentrations of ryanodine (5×10~ -5 ,10~ -4 ,2×10~ -4 mol·L~ -1 )could induce [Ca~ 2+ ]i increase in primary cultured ASMCs, but the increase of [Ca~ 2+ ]_i in primary cultured ASMCs of asthmatic guinea-pig was much higher than those of control group(P<0.01). In subcultured ASMCs of asthmatic guinea-pig, although in the presence of 5×10~ -5 mol·L~ -1 ryanodine, the increase of [Ca~ 2+ ]i was not so high as in primary cultured ASMCs(P<0.01), in the presence of 10~ -4 、2×10~ -4 mol·L~ -1 ryanodine, the increase of [Ca~ 2+ ]_i in both primary cultured ASMCs of asthmatic guinea-pig and subcultured ASMCs of asthmatic guinea-pig was at the similar level(P>0.05). ② In extracellular Ca~ 2+ -free condition, histamine (10~ -4 mol·L~ -1 ) induced changes of [Ca~ 2+ ]_i in primary cultured ASMCs of both asthmatic and control group was not significantly different (P>0.05). Conclusion Ryanodine receptor of asthmatic guinea-pig showed hypersensitivity. Under specified condition, the characteristics of ryanodine receptor still retains in subcultured ASMCs of asthmatic guinea-pig.