高频超声照射下血卟啉(HP)对脱氧核糖核酸(DNA)结构的影响

Damage of DNA under Irradiation of High-frequency Ultrasound in the Presence of Hematoporphyrin

采用紫外-可见(UV-Vis)光谱和荧光(FL)光谱研究了超声波照射激活光敏性化合物-血卟啉(HP)对脱氧核糖核酸(DNA)的损伤作用。在超声波和HP的协同作用下,在UV-Vis光谱中DNA溶液的吸光度表现出明显的增色效应,在FL光谱中DNA-EB溶液的荧光强度表现出明显的猝灭现象。考察了在超声波照射和HP存在的条件下,各种因素(如超声波照射时间,HP浓度和溶液酸度等)对DNA损伤程度的影响。结果表明,在一定条件下,DNA的损伤程度随着超声波照射时间的增长和HP浓度的增加而增大。溶液酸度对DNA损伤程度的影响较为复杂。当溶液为弱酸性和中性时对DNA的损伤较为明显,弱碱性时对DNA的损伤程度则又呈下降趋势。另外,在超声波损伤DNA的同时,溶液中的HP浓度也呈现出明显的下降趋势,说明HP也遭到了破坏。同时还探讨了超声波照射激活HP对DNA损伤的可能机理,认为对DNA损伤的现象可以采用"声致发光"和"热点"形成的机理进行解释。

In this paper, the damage of deoxyribonucleic acid （DNA） under the action of photosensitive compound, hematoporphyrin（HP） , activated by ultrasonic irradiation has been investigated by means of UV- Vis and fluorescence（FL） spectra. Under the cooperative action of ultrasonic irradiation and HP, the UV-Vis absorbence of the DNA solution showed obvious hyperchromic effect, while the fluorescence intensity of the DNA-EB solution exhibited evident quenching phenomenon. The influence of ultrasonic irradiation time, HP concentration and solution acidity on the damage of the DNA under ultrasonic irradiation in the presence of HP was also studied. The results showed that, under certain conditions, the damage of the DNA would be enhanced with the increase of ultrasonic irradiation time and HP concentration. However, the influence of solution acidity on the damage of the DNA was more complicated. In weak aeidic or neutral solutions, the damage of the DNA was obvious, but the trend decreased for basic solutions. In addition, the HP concentration also decreased, which indicated that the HP was destroyed, too. The possible mechanism on the damage of the DNA under ultrasonic irradiation in the presence of HP was also discussed, which explained such damage of the DNA by the theories of sonolumineseenee and ＂hot spot＂. These results may provide some guidances for the sonodynamic treatment（SDT） of various cancers in clinic in the future.