Effects of light quantum and hematoporphyrin therapy on the growth of tumor in rats

AIM:To study the effect of photodynamic therapy on the growth of tumor in rats.METHODS:W256 tumor cells were implanted in 40 rats by subcutaneous vaccination at groin.Then,the rats were treated by photodynamic therapy (PDT).Total saperoxides dismutase (T-SOD) and malondialdehyde (MDA) in plasma,tumor tissue and liver were detected.RESULTS:(1) The growth of tumor was significantly slow after the rats were transfused blood with ultraviolet radiation,with hematoporphyrin or with both ultraviolet radiation and hematoporphyrin (P<0.05,P＜0.01).(2) The activity of SOD was obviously increased and the contents of MDA were decreased in plasma while the growth of tumor was significantly slow in the ultraviolet radiation group (P<0.05,P＜0.01).However,the activity of T-SOD was weakened and the contents of MDA were increased in hematoporphyrin group (P<0.01) and ultraviolet radiation combined with hematoporphyrin group (P<0.01).CONCLUSIONS:The results indicate that the growth of tumor is inhibited by means of transfusion blood with ultraviolet radiation of hematoporphyrin.The most remarkable inhibitory effect is in ultraviolet radiation and hematoporphyrin group.The generation of singlet oxygen by PDT may be one of the mechanisms of killing tumor cells.