PATHOLOGIC CHANGES IN ADRENALECTOMIZED AND NON-ADRENALECTOMIZED RATS EXPOSED TO COLD1

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Abstract
Sexually mature male rats of the Sprague-Dawley strain were sensitized by removal of one kidney and feeding a diet containing 4 per cent sodium chloride. Adrenalectomized rats were treated with 4 cc. of aqueous adrenal cortical extract per rat per day. Groups of adrenalectomized and non-adrenalectomized rats were each subdivided into groups which were adapted to low temperature and kept at 3-5[degree]C for 60 days, and similar groups kept at room temperature for the same period of time. An additional group of non-adrenalectomized sensitized rats were adapted to the overfeeding of the high salt diet by stomach tube. The amount of fluid diet represented approximately as much dry diet as was eaten ad libitum by the cold-exposed rats. The following points were established 1. The rats exposed to cold ate much more food but gained less weight than did rats kept at room temperature. The rats which were overfed at room temperature became overweight. 2. The adrenalectomized rats treated with adrenal cortical extract at room temperature developed more microscopic damage to the hearts and kidneys than did non-adrenalectomized rats at room temperature, but there was no significant difference in organ weights or in the ratings of gross pathology. It was postulated that the adrenal cortices may modify their secretion of hormones in order to facilitate the excretion of a high salt load. Adrenalectomized rats on a fixed intake of replacement therapy may be at a disadvantage in this situation. 3. When the rats were exposed to cold the gross and microscopic damage to hearts and kidneys were equally marked in adrenalectomized and in non-adrenalectomized rats. There was hypertrophy of hearts and of kidneys in all rats exposed to cold. 4. Rats which were overfed at room temperature showed microscopic damage to hearts and kidneys almost as severe as that seen in the rats exposed to cold. 5. The role of the adrenal glands in causing the pathology which occurred in the cold-exposed rats is uncertain, for two reasons. Food intake was not constant. The amount of adrenal cortical extract used as replacement therapy in the adrenalectomized rats was associated with more damage than occurred in the non-adrenalectomized rats when the comparison was made at room temperature.