中文摘要：

目的：了解低强度激光照射对软骨细胞增殖的影响及其机制。方法：选取3周龄新西兰白兔分离培养软骨细胞，在2．5％新生牛血清中培养，用半导体激光（650nm，2．96mW／cm^2）（semiconductor laser irradiation，SLI）照第4代软骨细胞，每天分别照射1min、3min、5min、7min、10min、20min，共6d。收集激光照射后第2d、4d、6d、8d、10d和12d的细胞培养液，用氯胺T消化法检测羟脯氨酸（Hrp）的含量。在培养至第13d时，用XTT法检测细胞的活性，了解细胞的增殖情况。结果：在2．5％新生牛血清中，SLI对软骨细胞具有明显的光生物调节作用：（1）在培养至第13d时，所有剂量组在照射后XTT吸光度值均有不同程度的增高，其中3min、5min、7min和10min组的增高较为明显（P〈0．01）；（2）两因素重复测定资料的方差分析结果显示，SLI照射后软骨细胞合成胶原的能力在逐步增加，而对照组在培养至第2周开始Hrp含量明显下降。结论：SLI照射可促进2．5％新生牛血清中兔软骨细胞增殖，这个过程可能是通过促进胶原合成实现的。

英文摘要：

Objective：the effects of low intensity laser irradiation on the chondrocyte proliferation and its mechanism were studied. Methods： the chondrocytes isolated from the cartilage sample of 3-week-old New Zealand white rabbits were cultured with 10 % newborn calf serum （NCS）, irradiated by 650 nm semiconductor laser irradiation （SLI） at 2.96 mW/cm^2 for 1 min, 3 min, 5 min, 7 min, 10 min and 20 min per day for 6 days, and then incubated till the 13th day at 2.5 % NCS. The type Ⅱ collagen synthesis was assessed by a hydroxyproline （Hpr） content measurement on the 2nd, 4th, 6th, 8th, 10th and 12th day after the first SLI irradiation, respectively. The proliferation on the 13th day was assessed by a XTY assay. Results：There is significant photobiomodulation on the proliferation of the chondrocytes cultured at 2.5 % NCS. （ 1 ） The chondrocyte proliferation was significantly （ P 〈 0.01 ） promoted for the groups irradiated by SLI for 3,5,7 and 10 min, respectively, on the 13rd day; （2） The type II collagen synthesis increased steadily with days in the group irradiated by SLI for 5 min. Conclusions ： the proliferation of the chondrocyte cultured at 2.5 % NCS might be promoted by SLI, which might be mediated by collagen synthesis.