Piotron pion irradiation of cerebral capillaries in neonatal rats
Tóm tắt
The microvasculature of the neonatal rat brain and its radiation-induced petechial hemorrhages were used as an in vivo model for studying the effect of negative pions on healthy normal tissue. By means of dose response curves (range: 2–6 gray) the RBE of peak pions with respect to 220 kVp X-rays was calculated. Whereas earlier studies involved irradiations with single beam pions (πE3) of low dose rate (0.06–0.11 Gy per min) the present work was performed using pions of a multiport applicator (Piotron) of higher dose rate (1 Gy per min). The results obtained by Piotron pions agreed well with those obtained byπE3 pions resulting in a RBE of 1.1. The difference between pion and X-rays, however, was statistically not significant. 0-(beta-hydroxyethyl)-rutosides known for their protective effect on radiation damage induced by either X-rays or electrons were used for evaluating any radioprotective effect on pion-induced damage of the microvasculature. They were applied subcutaneously in doses of 450 mg/kg body weight 30 min prior to irradiation. It could be demonstrated that the rutosides decreased the pion-induced radiation response significantly by a factor of 1.3.
Tài liệu tham khảo
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