Gantchev T G, Urumov I J, Hunting D J, Van Lier J E
Department of Nuclear Medicine and Radiobiology, Faculty of Medicine, University of Sherbrooke, Quebec, Canada.
Int J Radiat Biol. 1994 Mar;65(3):289-98. doi: 10.1080/09553009414550341.
The photosensitizing properties of tetrasulphonated Al- and Zn-phthalocyanines (AlPcS4 and ZnPcS4) in lymphoma cells were studied as a function of the pre/post-illumination incubation time. Photocytotoxicity increased with incubation time, ranging from a transient cell-cycle arrest to cell killing. Under all experimental conditions, the phototoxicity of ZnPcS4 was markedly higher than that of AlPcS4. The primary photoprocesses initiated by metallo-phthalocyanines (MePcS4) in the cells were probed with DMPO/esr spin-trapping techniques. Under all incubation conditions the intracellularly bound MePcS4 sensitized formation of three different types of DMPO spin-adducts: DMPO/OH (hydroxyl radical), DMPO/R (organic carbon-centred radical(s)) and an unidentified simple nitroxyl, referred to as DMPO/ox. The yields of trapped radicals depended on the length of the incubation with the dyes prior to illumination and the formation of spin-adducts was shown to be intracellular. The ability of DMPO to protect cells from the photocytotoxic effects of Al- and ZnPcS4, combined with the generation of carbon-centred spin-adducts is direct evidence for the involvement of free-radical-mediated damage of cellular constituents.
研究了四磺化铝酞菁和锌酞菁（AlPcS4和ZnPcS4）在淋巴瘤细胞中的光敏特性与光照前/后孵育时间的关系。光细胞毒性随孵育时间增加，范围从短暂的细胞周期停滞到细胞杀伤。在所有实验条件下，ZnPcS4的光毒性明显高于AlPcS4。用DMPO/esr自旋捕获技术探测了金属酞菁（MePcS4）在细胞中引发的初级光过程。在所有孵育条件下，细胞内结合的MePcS4敏化形成三种不同类型的DMPO自旋加合物：DMPO/OH（羟基自由基）、DMPO/R（以有机碳为中心的自由基）和一种未鉴定的简单硝酰基，称为DMPO/ox。捕获自由基的产率取决于光照前与染料孵育的时间长度，并且自旋加合物的形成显示是在细胞内。DMPO保护细胞免受AlPcS4和ZnPcS4光细胞毒性作用的能力，以及以碳为中心的自旋加合物的产生，是自由基介导的细胞成分损伤参与的直接证据。
