STUDIES ON THE NAD(P)H PHOTOOXIDATION SENSITIZED BY HEMATOPORPHYRIN DERIVATIVE
血卟啉衍生物光敏引起NAD(P)H氧化作用研究

The luminol chemiluminesence in the photosensitized oxidation of NAD(P)H was found to be dependent upon many factors such as pH,laser density, irradiation time,concentrations of luminol, HPD and NAD(P)H.When the concentration of NAD(P)H was far more excessive as compared with that of hematoporphyrin derivative (HPD) , the intensity of CL was positively proportional to the concentration of HPD, which implied that the CL measurement can be used as an indicator for the detection of photosensitized oxidation and that the CL may be generated by the photooxidation of NAD(P)H in the presence of reactive oxygen species(ROS). By selectively using scavengers of O2,H2O2, OH and quenchors of 1O2 the actions of ROS and 1O2 involved in the photoensitized oxidation of NAD(P)H by HPD were obviously identified. The experimental results were briefly summerized as follows:(1) The CL emitted from the photooxidation of NAD(P)H was depressed by copper-zinc superoxide dismutase(CuZn-SOD) ,catalase(CAT)and sodium formate (F) in aqueous solution aa well as by histionine (Met) and methiorin(Met) in deuterium oxide. The inhibition percentage of CL by the addition of 1?g/ml Cu Zn-SOD was 84%,but that by adding the enzyme in excess did not increase any more.The inhibition style by CAT was the same as CuZn-SOD,and the inhibition by F was relatively weak,in the range of 14-42 mM F, the inhibition did not exceed 60%.(2) The inhibition of CL by CuZn-SOD was decreased along with the duration time of irradiation of laser,wherean that by CAT or F was increased in the same condition and the effects of His and Met were more complicated.(3) The inactictivation of NAD(P)H,indicated by the changes of OD340,was prevented by ROS scavengers in aqueous as well as by His and Met in deuterium oxide soultion.It has been demonstrated that a parallel ralationship between the inhibition of CL and the prevention of inactivation of NAD(P) H by ROS scavengers or 1O2 quenchors existed.