RESUMEN
PURPOSE: Because of the crucial practical importance of acute radiation exposure associated with combined injuries, the study was undertaken to investigate the effect of various doses of ascorbic acid on the survival and healing of wounds in mice exposed to whole-body gamma-radiation. MATERIALS AND METHODS: Animals were given double-distilled water or different doses of ascorbic acid by intraperitoneal injection before exposure to 0 or 10 Gy whole-body gamma-radiation to evaluate the effect of ascorbic acid on radiation-induced mortality. The animals were monitored daily for the symptoms of radiation sickness and mortality. In a separate experiment, animals were administered with either double-distilled water or different doses of ascorbic acid before exposure to 0 or 6 Gy whole-body gamma-radiation to investigate the effect of ascorbic acid on the irradiated wound. A full-thickness skin wound was created on the dorsum of the irradiated mice and the progression of wound contraction was monitored by capturing video images of the wound at various post-irradiation periods. RESULT: Treatment of mice with various doses of ascorbic acid elevated survival of mice and a highest number of survivors (67 and 33% for 10 and 30 days post-irradiation) was observed for 250 mg kg(-1) (p<0.002 and<0.02 for 10- and 30-day survival, respectively). Ascorbic acid treatment caused a dose-dependent elevation in the wound contraction and highest contraction was observed for 250 mg kg(-1). The wound contraction was significantly greater at 3 (p<0.005), 6 (<0.05) and 9 (<0.05) days post-irradiation with 250 mg kg(-1) ascorbic acid. The complete healing of the wound was effected by day 22.8 post-irradiation in the ascorbic acid-treated irradiation group. CONCLUSION: Administration of ascorbic acid protected mice against radiation-induced sickness, mortality and improved healing of wounds after exposure to whole-body gamma-radiation. Additional studies will be directed toward analysing the role of successive administration of ascorbic acid to protect non-target tissues during radiotherapy and in initiating and supporting the cascade of tissue repair processes in radiotherapy delayed wounds.