不同时间氦-氖激光照射对兔跟腱愈合的影响

The effect of different times of He-Ne laser irradiation on healing of rabbit achilles tendons

目的研究不同时间氦-氖(He-Ne)激光照射对跟腱损伤兔的组织形态以及Ⅰ型和Ⅲ型胶原蛋白含量的影响,探讨He-Ne激光照射促进跟腱愈合的最佳时间。方法选取20只新西兰雄兔,兔龄10～12周,分为对照组5只和激光照射组15只。对照组跟腱切断缝合手术后不进行激光照射;激光照射组于术后第1天即用低功率He-Ne激光(波长为632.8nm、功率为18.9 mW)经皮损伤部位行光斑扩束照射,每日照射1次,共照射14d。激光照射组再根据每次照射时间的长短分为激光照射10min,20min和30min组,每亚组各5只。于实验第28天处死各组兔,采集跟腱标本,采用HE染色和胶原纤维的Van Geison染色法观察跟腱组织形态学的变化,采用SDS-PAGE电泳法及光密度扫描法检测各组跟腱组织的Ⅰ型、Ⅲ型胶原蛋白含量。结果HE染色显示,激光照射20min组胶原纤维致密、增粗,并含有血管和功能活跃的腱细胞、巨噬细胞。激光照射20min组Van Geison染色可见较成熟的粗大胶原纤维间质,排列层次接近正常跟腱组织。各激光照射组Ⅲ型胶原蛋白含量均高于对照组(P<0.05),激光照射20min组与激光照射10min组比较,差异有统计学意义(P<0.05),与激光照射30min组比较,差异无统计学意义(P>0.05)。结论每日He-Ne激光照射20min,连续28d能促进跟腱损伤兔组织胶原蛋白的合成,加速跟腱组织的愈合。

Objective To evaluate the influence of duration of laser irradiation on histomorphometric measurements in experimentally tenotomized and repaired rabbit Achilles tendons and to explore the best irradiation time. Methods A total of 20 male New Zealand rabbits aged 10 - 12 weeks were used and randomly divided into 4 groups： a control group and three experimental groups. All the animals underwent surgical excised and then repair of their Achillis tendon. The animals in the control group were then treated with sham laser irradiation, while those in the three experimental groups were treated with 10, 20 and 30 minutes of He-Ne laser irradiation （632. 8 nm, 18.9 mW ） daily, respectively, for 14 days. On the 28th day after surgical operation, the animals were sacrificed and their Achilles tendons were sampled. HE stain and Van Geison stain were used to observe morphometric changes of tendons. The SDS-PAGE electrophoresis method and CS-930 photodensity scan instrument were employed to measure the content of types I and III collagen. Results It was shown that laser irradiation enhanced cell proliferation, cellular content, granulation tissue formation and collagen deposition in laser-treated tendons, especially in those irradiated for 20 minute daily, as compared to the control group. Type Ⅰ and type Ⅲ collagen levels were significantly increased at the 28th day in the healing tendons and the ratio of collagen ⅢI to Ⅰ increased in all the 3 experimental groups, and the increase of both collagen content and ratio of collagen type III to I was significantly greater in those irradiated 20 minutes daily （P 〈 0.05 ）. Conclusion Laser irradiation can facilitate tendon healing in rabbits, and this might be achieved by increase the collagen production. The best daily irradiation time is 20 minutes.