Reed M W, Schuschke D A, Miller F N
Department of Surgery, University of Sheffield, United Kingdom.
Radiat Res. 1991 Sep;127(3):292-6.
Microcirculatory shutdown appears to be of central importance in the mechanisms of action of photodynamic therapy (PDT). Traditionally 24-48 h are allowed between the administration of the photosensitizer and light to allow for tumor localization. However, previous studies have shown that the effects of PDT on the microcirculation are maximal soon after administration of the photosensitizer when serum levels are highest. This study involved the use of television video microscopy of the cremaster muscle microcirculation of male Sprague-Dawley rats to study the involvement of prostanoids in the effects of PDT on the microcirculation 30 min after administration of photofrin II. Pretreatment with topical indomethacin resulted in an altered response to PDT with arteriolar dilation and delay in vessel shutdown. The thromboxane A2 antagonist SQ29548 (100 mg/kg/min iv) resulted in a significant delay in platelet thrombus formation in arterioles and venules. These results indicate that prostanoids are involved in the mediation of the response of the normal microcirculation to PDT.
微循环关闭在光动力疗法（PDT）的作用机制中似乎至关重要。传统上，在给予光敏剂和光照之间允许24 - 48小时，以便肿瘤定位。然而，先前的研究表明，当血清水平最高时，PDT对微循环的影响在给予光敏剂后很快达到最大。本研究利用雄性Sprague-Dawley大鼠提睾肌微循环的电视视频显微镜技术，研究前列腺素在给予Photofrin II 30分钟后PDT对微循环影响中的作用。局部应用吲哚美辛预处理导致对PDT的反应改变，出现小动脉扩张和血管关闭延迟。血栓素A2拮抗剂SQ29548（100毫克/千克/分钟静脉注射）导致小动脉和小静脉中血小板血栓形成显著延迟。这些结果表明，前列腺素参与介导正常微循环对PDT的反应。
