内皮素对瘢痕成纤维细胞增殖和胶原合成作用的实验研究

目的：探讨内皮素（ET）在瘢痕成纤维细胞增殖与胶原合成中的作用及一氧化氮（NO）、粉防已碱（Tet）的拮抗效应。方法：体外培养人增生性瘢痕成纤维细胞，以^3H-TdR掺入法测定细胞增殖；以^3H-脯氨酸掺入量判断细胞胶原合成。结果：ET呈浓度依赖性促进瘢痕成纤维细胞增殖与胶原合成，随着ET浓度（2．5－100ng/ml）的增加，^3H-TdR掺入值较对照组分别增加了1．8、4．0和4．9倍；^3H－脯氨酸掺入值较对照组分别增加了1．1、3．1和3．8倍（P＜0．01）。用NO供体亚硝基乙酰青霉胺（S-nitroso-N-acetyl penicillamine,SNAP)50μg/ml单独处理成纤维细胞，对^3H-TdR掺入值无明显影响（与对照组相比，P＞0．05），但对^3H-脯氨酸掺入值有下调作用；SNAP可拮抗ET－1（25ng/ml）刺激细胞增殖作用（抑制率为22．89％，P＜0．05）；对ET－1的促胶原合成作用无明显影响（P＞0．05）。Tet在不抑制细胞DNA合成的药物浓度（3μg/ml）即可明显减少瘢痕成纤维细胞^3H-脯氨酸掺入值，并能显著降低由ET介导的瘢痕成纤维细胞^3H-TdR掺入值（抑制率为33．21％，P＜0．01）。结论：ET对体外培养的瘢痕成纤维细胞增殖与胶原合成具有显著促进作用，此效应可部分被SNAP、Tet所阻抗。

Experimental study on effects of endothelin in the proliferation and collagen synthesis of human scar-derived fibroblasts

OBJECTIVE: To investigate the role of endothelin (ET) in the proliferation and collagen synthesis of human scar-derived fibroblasts and the modulation of its antagonists such as nitric oxide (NO), tetrandrine (Tet). METHODS: With the cultured fibroblasts from the scarring tissue, the cell proliferation was determined by [3H]-TdR incorporation, while the collagen synthesis was evaluated by [3H]-proline incorporation. RESULTS: The ET-1 was significantly increasing the proliferation and collagen synthesis of human scar-derived fibroblasts. The values of [3H]-TdR absorption in the 2.5 ng/ml, 25 ng/ml and 100 ng/ml of ET-1 groups were 1.8 times, 4 times and 4.9 times more than in the control group, respectively (P < 0.01), while the values of the [3H]-proline incorporation were 1.1 times, 3.1 times and 3.8 times respectively (P < 0.01). The fibroblasts, treated with 50 micrograms/ml of S-nitroso-N-acetyl penicillamine(SNAP), were no detectable effect on the basal level of DNA synthesis, but produced decreasing effect on the [3H]-TdR absorption (the rate of inhibition was 22.89%, P < 0.05). It was found that the SNAP inhibited the [3H]-proline incorporation in cultured fibroblasts, but the rate of [3H]-proline incorporation induced by ET-1 was unaltered. The Tet with 3 micrograms/ml, in which does not inhibit the basal level of DNA synthesis, was significantly decreasing the collagen synthesis and decreasing the ET-mediated DNA synthesis (the rate of inhibition was 33.21% (P < 0.01). CONCLUSION: These results indicate that the ET can obviously increase the proliferation and collagen synthesis of human scar-derived fibroblasts, but it can be partially antagonized by NO and Tet.