ACTION SPECTRUM OF DNA SYNTHESIS INHIBITION AFTER FEMTOSECOND ILLUMINATION

光动力疗法通常被认为是针对线粒体的 当使用卟啉和其它光敏剂时。 我们已经使用 细胞NAD（P）H的多光子代谢成像，以监测 Photofrin，一种卟啉光敏剂。 Photofrin和 NADH可以同时被750 nm的多光子激发 辐照 在单层细胞和多细胞肿瘤球体中， Photofrin可使NAD（P）H减少约2倍 自发荧光 从自发荧光的观察， 摄取，似乎这种减少是同时与Photofrin 进入质膜。 在PDT过程中，观察到NAD（P）H 对于相对较短的辐照，以剂量依赖性方式降低。 没想到，这一趋势最终发生逆转，信号已被 观察到从PDT前水平增加多达5倍， 疗法 我们目前正在评估这些问题的重要性。 观察和测试可能解释 这种行为。

Photodynamic therapy is commonly believed to target mitochondria when porphyrin and other photosensitizers are employed. We have used multiphoton metabolic imaging of cellular NAD(P)H as to monitor the effects of Photofrin, a porphyrin photosensitizer. Both Photofrin and NADH can simultaneously be multiphoton excited with 750 nm irradiation. In both monolayer cells and multicell tumor spheroids, Photofrin is seen to cause approximately two-fold reduction of NAD(P)H autofluorescence. From observations of autofluorescence during uptake, it appears that this decrease is concurrent with Photofrin entering the plasma membrane. During PDT, NAD(P)H is observed to decrease in a dose dependent manner for relatively short irradiations. Unexpectedly, this trend eventually reverses and the signal has been observed to increase as much as 5 fold from pre-PDT levels during therapy. We are currently assessing the significance of these observations and testing hypothetical mechanisms that might explain this behavior.