【摘要】 将人类肝癌细胞,7703株,悬于PBS中,与血卟啉一起在37℃保温一小时;然后用340—370nm的紫外线在40℃照射32分钟(～3.94×10^-2J/cm²·min)用Fornace和Kohn的与蛋白酶处理相结合的碱液洗脱法测定细胞DNA的单链断裂和交联。得到三个结果:（1）在细胞与血卟啉（3.1—50.0μg/ml）一起保温的一小时中,发生DNA降解。（2）血卟啉（50μg/ml）的光敏化作用会使DNA交联作用增多1倍（P<0.01）。（3）在血卟啉光敏化作用所产生的交联物中的DNA,有87％是与蛋白质交联的。由于血卟啉促进细胞DNA交联作用尚未见于以往文献,作者认为在考虑用血卟啉作敏化剂的癌的光辐射治疗中细胞杀伤机制时,不能忽视这种现象。更多还原

【Abstract】 Human hepatocarcinoma cells, line 7703, suspended in PBS wereincubated with hematoporphyrin （HP） at 37℃ for an hour and then irradiated by340-370 nm UV for 32 minutes (～3. 9× 10^-2 J/cm·² min) at 4℃. The Fornace andKohn’s method of alkaline elution combined with protease treatment was used formeasuring the SSB and crosslink of cell DNA. Three results were obtained: （1 ） CellDNA degradation occurred in incubating the cells with HP （3. 1-50.0μg/ml） foran hour. （2） The HP （50μg/ml） photosensitization enhanced the cell DNA crosslin-king by a factor of 2. （3） About 87% of the DNA in crosslinked substance inducedby UV in the presence of HP is linked with protein. The enhancement of DNA cross-linking by HP photosensitization reported here has not been found in previous papersso the authors suggest that this phenomenon shoud not be overlooked in consideringthe mechanisms of cell killing in photoradiation therapy of cancer using HP as thephotosensitizer.更多还原