[Thyroid gland hypofunction during separate and combined radiation-thermal injury]

A study was made of the dynamics of structural, morphological and histological changes in the thyroid gland of Wistar rats subjected to gamma-irradiation (7.5 Gy) and thermal burn (15% of a body surface) and a combined effect of these two factors. Concurrently, an estimation was made of the iodine content of the gland, using the roentgen-fluorescent method, and of the thyroxin concentration in blood. The results obtained were considered in relation to the clinical course and the outcome of the affection caused by the combined and individual effects of radiation and heat. It is conluded that the cell-tissue substrate providing the thyroid hormones synthesis does not undergo substantial variations from normal values which could be considered as a cause of the decrease in the hormone content of blood after burn, irradiation and the combined radiation and thermal injury. Other possible causes of hyperthyroxynemia are discussed.