The Application And Mechanism Of Acute Radiation-induced Skin Injury Therapy With Vit B12

Objective:To investigate the application and mechanism of Vit B12 in acute radiation-induced skin injury.Methods:(1)75 normal male SD rats aged 2～3 months were selected.the rats were irradiated with 45 Gy electron ray after shaving their buttocks and backs to establish the model of radiation-induced skin injury in order to observe the general appearance of the irradiated area.(2)After irradiation,the rats were equally divided into three groups:group A(blank control group),group B(physiological saline injection group)and group C(Vit B12 injection group).Physiological saline and Vit B12 were injected with microneedle electron syringe in the subcutaneous and dermis of the irradiated area.the injection time was immediately after radiation and every day for 2 weeks.(3)Blood samples were collected at 2h,24h and 48h after irradiation.the expression of inflammatory factors TNF-α,IL-1 βand IL-6 in peripheral blood of rats in each group was detected and compared by ELISA.(4)The appearance of rat models was compared every 3 days.The wound tissue of rats was cut every week so as to observe the pathological changes and microvessel count in each group after 1,2 and 3 weeks by HE staining.Results:(1)About 2 weeks after irradiation,obvious congestive erythema appeared on the skin.About 3 weeks,blisters and dry scabs appeared;then one week later,erosion and necrosis of skin tissue formed ulcers.After Vit B12 injection,erythema and ulcer formation rate of rats in group C was significantly slower than that of group A,so was the level of skin injury.(2)2 weeks after irradiation,HE staining of wound skin of rats showed that the number of microvessels in group A and group B was significantly decreased,and there was no statistically significant difference between group A and group B(P>0.05).While group C had more microvessels,and the difference was statistically significant(P<0.01)after comparing with group A and B,respectively.(3)The concentration of inflammatory factors in group C was significantly lower than that in group B,and the difference was statistically significant(P<0.01).Conclusion:(1)When the total dose of electron line generated by medical electron linear accelerator is 45 Gy,the animal model of radioactive skin injury can be successfully established.The method is simple,accurate and reliable.(2)Vit B12 can effectively intervene the occurrence and development of radioactive skin injury in rat models,which may be related to the improvement of microcirculation status at the radiation site by protecting vascular endothelial cells,preventing vascular obstruction and vascular thrombosis.(3)Vit B12 may reduce the irritation and pain of radioactive skin injury by lowering levels of inflammatory factors.