Lowered Resistance to Heat in Adrenal Insufficiency.

Abstract

Gautrelet and Thomas observed that the rapid breathing usually produced by exposure to high temperatures was absent or very much reduced in the late stages of adrenal insufficiency. In our care of adrenalectomized animals in the laboratory, we have found that high temperatures affect these animals easily. When accidentally overheated, they die before the normal animals. A study has been made of the effect of heat on adrenalectomized rats. When placed in a temperature of 37-40°C. at first both normal and adrenalectomized rats move about the cage. A little later, however, the adrenalectomized animals become quiet and try to sleep, only occasionally moving about. As time goes on the adrenalectomized animals become prostrate while the normal animals show discomfort only by continually moving about the cage and washing themselves with saliva. Frequently the adrenalectomized animals die in a temperature which is not serious for the normals exposed the same length of time. The adrenalectomized animals easily pass into convulsions. At this time convulsions can be brought on by a slight stimulus. Cortical extract can protect adrenalectomized animals to a considerable degree. If cortin injected and sodium chloride injected (0.5 cc. twice daily of extract and isotonic NaCl solutions respectively) rats which have been adrenalectomized are placed in the same high temperature, the difference between the 2 is much like that between normal animals and untreated; adrenalectomized animals except that it is not quite so striking. We are unable at present to explain this increased resistance brought about by cortin. It will be noted that the water content of the blood and muscle shows the least difference in the various groups. The liver comes next while the skin shows the widest differences.