Abstract
It is well known that adrenalectomized animals resist cold poorly. This appears to be due to cortical rather than medullary deficiency, because cortical transplants enable adrenalectomized rats to resist cold well. 1 In the present study we have been able to show that an extract of the adrenal cortex protects adrenalectomized rats so that they resist cold very well.
Two series of rats were completely adrenalectomized at one operation. The rats in series A (20 rats) were adrenalectomized 10 to 25 days before the experiment with cold. These were protected by injection of cortical extract twice daily (the product from 15 to 25 gm. of cortex each time). The rats in series B (19 rats) were adrenalectomized 4 to 25 days before the experiment. These were injected with the same volume of isotonic NaCl solution at the same time that the cortical extract was given to those in series A.
One extra injection of 0.5 cc. of the respective solutions was administered 12 hours before starting the test with cold, and others as follows: 4 hours before (0.5 cc.), at the test (0.4 cc.), and 4 hours after starting the test (0.5 cc.).
The rats had lived all their lives at a temperature of 27°C. The rats of series A and B together with 6 normal rats of the same weights were exposed to a temperature which gradually fell from 13°C. to 8°C. in 10 hours, when they were again placed in the warm room (27°C.).
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