中文摘要：

目的探讨激活素A对小鼠纤维母细胞L929活性的调节作用。方法用不同剂量的激活素A刺激L929细胞，应用还原酶法分析细胞分泌一氧化氮（NO）的水平，RT-PCR法检测细胞诱导型一氧化氮合成酶（iNOS）、纤维连接蛋白（FN）和金属蛋白酶组织抑制物（TIMP）mRNA的表达，应用中性红检测细胞的吞饮活性，MTT法检测细胞的增殖活性。结果L929细胞经激活素A刺激后，与对照组细胞比较，分泌NO的水平明显升高，iNOS mRNA及FN mRNA的表达水平也升高，而TIMP mRNA的表达水平无明显改变。激活素A可以促进L929细胞的吞饮活性，但对L929细胞的增殖活性无影响。结论激活素A具有促进L929细胞分泌炎性介质和形成细胞外基质的作用，这可能是其促进炎症发展、诱导组织纤维化的原因。

英文摘要：

Objective To explore the regulatory effect of activin A on the activity of L929 cells. Methods L929 cells were stimulated with activin A at various concentrations. The level of nitrogen oxide secreted by L929 cells were determined by Griess method, the expressions of mRNAs of inducible nitric oxide synthase （iNOS）, fibronectin （FN） and tissue inhibitor for metalloproteinase （TIMP） by RT-PCR, the pinocytosis of L929 cells by neutral red test, and the cell proliferation activity by MTT method. Results Compared with those of control, the secretion level of nitrogen oxide as well as expression levels of iNOS and FN mRNAs in L929 cells stimulated with activin A increased significantly, while the expression level of TIMP mRNA showed no significant change. Activin A promoted the pinocytosis, while showed no significant effect on the proliferation level of L929 cells. Conclusion Activin A promoted the secretion of inflammatory mediators and formation of extracellular matrix by L929 cells, which might be a reason for promoting inflammation development and inducing tissue fibrosis.