The effect of different times of He-Ne laser irradiation on healing of rabbit achilles tendons / 中华物理医学与康复杂志

ABSTRACT

Objective To evaluate the influence of duration of laser irradiation on histomorphometric meas- urements 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 groupsa 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 typesⅠandⅢcollagen.Results it was shown that laser irradiation enhanced cell proliferation,cel- lular content,granulation tissue formation and collagen deposition in laser-treated tendons,especially in those irradia- ted for 20 minute daily,as compared to the control group.TypeⅠand typeⅢcollagen levels were significantly in- creased at the 28th day in the healing tendons and the ratio of collagenⅢtoⅠincreased in all the 3 experimental groups,and the increase of both collagen content and ratio of collagen typeⅢtoⅠwas significantly greater in those ir- radiated 20 minutes daily(P