Effects of Exposure to Cold Upon Urinary Nonprotein Nitrogen and Electrolytes in Adrenalectomized and Nonadrenalectomized Rats

Abstract

Twelve male rats of the Sprague-Dawley strain were force-fed a fluid medium carbohydrate diet twice daily. 6 of the rats were adrenalectomized and treated with 4 ml. of ACE daily throughout the expt. The remaining rats were given equal volumes of 0.9% saline and served as nonadrenalectomized controls. All rats were exposed to cold during 2 separate expts. All rats exhibited the same general pattern of response to cold and recovery at normal temp. During exposure to cold (as low as It) the rats lost wt. and excreted increased amts. of nonprotein N and K. These changes were reversed when the temp, was elevated to 26%. When the temp, was elevated from 1[degree] to 26[degree], all rats showed a sharp increase in wt. and a decrease in the excretion of Na and chloride. This response lasted for only 24 hrs. None of the other variations in the excretion of Na and chloride were clearly related to a change in temp. These metabolic responses to cold which occurred in the absence of the adrenal glands must represent extra-adrenal regulatory mechanisms.