光动力疗法对犬正常呼吸道粘膜及其周围组织的影响

为了探索PDT在呼吸道应用的安全性,作者等将PDT用于正常犬呼吸道,观察比较常规静脉注射HpD、局部注射HpD、不注射HpD在不同功率密度的630nm波长激光照射下的组织反应。观察分照射后即刻,1天至4周,肉眼和光镜下组织学改变。实验证实正常呼吸道粘膜在全身给药后48小时照光仅有轻微的光敏损伤,照射激光的功率密度高于500mW/cm~2时,则产生明显的非特异性组织热损伤。因而在谋求真正的PDT作用时,激光的功率密度不宜超过500mW/cm~2。本文对光敏损伤与热损伤以及在呼吸道中PDT所使用的照射光功率密度的特点等问题进行了探讨。

The Impact of PDT on the Canine Tracheal Mucosa

In order to identify the safty of PDT on the respiratory tract, canine tracheal mueosa was irradiated by laser (wavelength 630nm) of various power densities in both experimental and control animals. HpD was given intravenously or topically in the erperimental groups Samples were examined by the naked eye and under light microscope immediately, or 1 day, 3 days, 1 week, 2 weeks and 4 weeks followed laser exposures. For subjects received intravenous administration of HpD, laser irradiation at 48 hours after RpD injection produced only slight mucosal injury. However, topical administration of the same agent resulted in substantial photodamago of the local mueosa. Light with power density of over 500mW/cm~2 induced notable non-specific thermo-injury of the local tissue. Photodynamic damage, thermo-injury and appropriate power density for application of PDT in respiratory tract are discussed.