牛磺酸对大鼠心肌成纤维细胞增殖的影响

观察牛磺酸(taurine，Tau)在血管紧张素II(angiotensin II，Ang II)诱导新生大鼠心肌成纤维细胞(cardiac fibroblast，CFb)增殖过程中对一氧化氮(nitric oxide，NO)及蛋白激酶C alpha(p-PKCα)的影响，以探讨牛磺酸抑制CFb增殖的信号转导途径。胰酶消化法分离培养新生大鼠CFb，用Ang II诱导促进其增殖，采用MTT法检测细胞增殖；ELISA法测定I型胶原、 III型胶原的含量；流式细胞仪检测细胞周期；硝酸还原酶法检测细胞上清液NO含量；Western blotting法检测p-PKCα含量。牛磺酸(40、 80和160 mmol·L^-1)可抑制Ang II诱导的CFb增殖及I型胶原、III型胶原合成增加(P<0.05，P<0.01)，并使细胞G₀/G₁期百分率增加，S期细胞百分率降低(P<0.05，P<0.01)。牛磺酸明显抑制p-PKCα的蛋白表达， 提高CFb NO含量， 与Ang II组比较差别具有明显统计学意义(P<0.05， P<0.01)。牛磺酸通过降低p-PKCα的表达而提高CFb NO的含量，使CFb的增殖和胶原合成受到抑制。

Effects of taurine on proliferation of rat cardiac fibroblast

This project aimed to investigate the effect of taurine on nitric oxide (NO) and protein kinase C alpha (p-PKCalpha) in the proliferation of cultured neonatal rat cardiac fibroblast (CFb) induced by angiotensin II (Ang II), and to explore the effect of taurine on the signal transduction pathway in CFb proliferation. The cultured neonatal rats CFb were isolated by trypsin digestion method. The proliferation of CFb was induced by Ang II and detected by thiazole blue (MTT) colorimetric assay. The levels of collagen I and collagen III were measured by the ELISA. Cell cycle was analyzed by flow cytometry. The change of NO content was measured by nitric acid reductase method and the protein express of p-PKCalpha in cells was determined by Western blotting technology. Among the concentration of 40 - 160 mmol x L(-1), taurine could not only prevent the synthesis of collagen and the proliferation of CFb stimulated by angiotensin II, but also block CFb in the G0/G1 phase from entering the S phase, resulting in more cells in the G0/G1 phase and fewer in the S phase (P < 0.05, P < 0.01). Taurine significantly increased NO level and inhibited p-PKCalpha expression in CFb (P < 0.05, P < 0.01). The inhibitory effects of taurine on CFb proliferation and collagen synthesis might be due to inhibition of p-PKCalpha expression and NO content increase.