中文摘要：

目的探讨刚地弓形虫侵入不同类型传代细胞过程中宿主胞内游离Ca^2＋和胞外花生四烯酸（AA）的变化和来源。方法采用核素液闪仪和激光共聚焦显微镜检测刚地弓形虫RH株侵入Veto和J774A.1细胞过程中宿主胞外AA和胞内游离Ca^2＋的变化及来源。对所获数据进行方差分析和t检验。结果弓形虫侵入J774A.1和Vero细胞后，宿主胞内游离Ca^2＋有不同程度升高，其最高荧光强度变化分别为（1219．7±58．4）％（t=4.982，P〈0.01）和（356.3±23．6）％（t=2.593，P〈0.05）。Vero细胞内Ca^2＋升高多来源于胞内Ca^2＋库释放，而J774A.1细胞内Ca^2＋升高来源于胞内Ca^2＋库释放和胞外Ca^2＋内流。弓形虫侵入Vero和J774A.1细胞后，宿主胞外AA均明显升高，分别为感染前的5.02倍和8.44倍（t=3.124，t=3.852，均P〈0.01）。磷脂酶怠抑制剂作用弓形虫后可明显抑制AA升高。结论弓形虫感染吞噬性细胞激活宿主胞膜磷脂酶C和弓形虫磷脂酶A2，引起宿主胞内游离Ca^2＋和胞外AA浓度升高，两者共同作用导致虫体侵入；虫体侵入非吞噬性细胞可能仅激活虫体磷脂酶A2。

英文摘要：

Objective To explore variance and resource of intracellular free Ca^＋ and extracellular arachidonic acid （AA） in different types of passage cells during the invasion of T. gondii, Methods The variance and resource of extracellular AA and intracellular free Ca^＋ of Vero and J774A.1 cells during the invasion of T. gondii were detected by multi-purpose scintillation counter and laser scanning confocal microscope. Data were analyzed using Chi-square test and t test. Results The intracellular free Ca^2＋ levels in J774A.1 and Vero cells were both increased after T. gondii infection. The maximal changes of fluorescence intensity were （1219.7±58.4）% （P〈0.01） and （356.3±23.6）%（P〈0.05）, respectively. The increase of intracellular Ca^2＋ level in Vero cell was mostly from the release of intracellular Ca^2＋ store. And the Ca^2＋ increase in J774A.1 cell was from both the release of intracellular Ca^2＋ store and extracellular Ca^2＋ influx. Extracellular AA levels were significantly increased in both Vero and J774A.1 cells after T. gondii infection 5.02 and 8.44 times respectively （t=3.124, t=3.852, P〈0.01）. The APt elevations could be significantly inhibited by phospholipase A2 （PLA2） inhibitor pretreating T. gondii. Conclusions The 15hospholipase C of phagocytic host cell and PLA2 of T. gondii are activated by T. gondii infection, which results in the increase of intracellular free Ca^2＋ and extracellular AA level. Combined actions of Ca^2＋ and AA play a major role in the invasion of T. gondii to host cell. While only PLA2 of T. gondii may be activated in nonphagoeytic host cell.