[The modifying effect of a hypoxic gas mixture on the development of radiation-induced sclerosis]

Female mice (CBA X C57 Bl) F1 were exposed a single total-body gamma-irradiation with a dose efficiency of 6.5 Gy/min with doses of 2.5-7.5 Gy in air or inhaling a gas mixture of 6-6.5% oxygen and 94-93% nitrogen. All naturally died animals were examined pathoanatomically. By means of the rate of cardio- and nephroscleroses a protective effect of hypoxia was found with a dose modification factor of 1.5. Dynamics and degree of intensity of a radiogenic pneumosclerosis were studied by means of a stereologic analysis 3, 6, and 12 months after a single roentgen irradiation of the right thorax half of rats with a dose efficiency of 2.2 Gy/min with doses of 10, 14.3, 20 Gy in air and 14.3 and 20 Gy inhaling a gas mixture with 10% oxygen and 90% nitrogen. Applying the criterion of accumulation of connective tissue within the irradiated lung the protecting effect of hypoxia was estimated according to the dose modification coefficient, that varied in a range of 1.0-1.64.