实电解质钙可诱发人肥大细胞组胺和类胰蛋白酶分泌

CALCIUM IONOPHORE INDUCED HISTAMINE AND TRYPTASE RELEASE FROM HUMAN MAST CELLS

目的 :利用人大肠组织的肥大细胞和肥大细胞激活的体外研究系统 ,评价实电解质钙 (calciumionophoreA2 3187,CI)诱导肥大细胞释放类胰蛋白酶和组胺的能力和机制。方法 :经酶悬浮的人大肠肥大细胞与CI共同培养后收集上清液 ,并用酶联免疫吸附试验 (ELISA)的方法检测类胰蛋白酶分泌量 ,用以玻璃纤维为基础的荧光比色法检测组胺释放量。结果 :经过 15min的培养 ,CI可引起浓度相关性的组胺和类胰蛋白酶释放。其中组胺的最大分泌量比基础分泌量超出了 5 .3倍以上 ,而类胰蛋白酶的最大分泌量则比基础分泌量超出了 2 .8倍以上。CI在浓度高于 1.0 μmol/L时引起的组胺释放量明显多于类胰蛋白酶释放量。时间关系曲线显示 ,CI的作用从加样后 10s开始 ,6min后达高峰并至少持续 15min。百日咳毒素和代谢抑制剂均能抑制CI引起的组胺和类胰蛋白酶释放。结论 :人大肠肥大细胞在受到CI刺激时具有释放类胰蛋白酶和组胺的能力 ,这个过程与肥大细胞膜G蛋白偶联受体的激活有关 ,并消耗能量。

Aim: To examine the ability of calcium ionophore(CI) to induce tryptase and histamine release from human mast cells and its mechanisms. Methods: Enzymatically dispersed cells from human colons were challenged with CI, and the cell supernatants after challenge were collected. Tryptase release was determined with a sandwich ELISA procedure and histamine release was measured using a glass fibre-based fluorometric assay. Results: CI was able to induce a concentration dependent release of histamine and tryptase from human colon mast cells following 15 min incubation. The maximum of induced histamine and tryptase release were approximately 5.3 and 2.8 fold more than the levels of spontaneous release, respectively. CI at the concentrations higher than 1.0 μmol/L was able to induce significantly more histamine than tryptase release from mast cells. The time course revealed that the action of CI on mast cells started from 10 s, peaked at 6 min and lasted at least 15 min following incubation. Pertussis toxin and metabolic inhibitors were able to inhibit mast cell response to CI. Conclusion: Human colon mast cells were able to release tryptase and histamine in response to CI. The process seemed to be associated with the activation of a G-protein coupled receptor on the membrane of mast cells and requires cell energy supply.