Abstract
The responses of intact rats to cold-exposure (4°C) include vasoconstriction, piloerection, shivering, adrenocorticotrophin (ACTH) hypersecretion and increased mobilization of free fatty acids and glucose. Adrenal demedullation prevents the increased mobilization of glucose and decreases survival time. Chemical sympathectomy blocks all of the responses except ACTH hypersecretion. Such animals lose body heat rapidly and die in a few hours. Total adrenalectomy has a similar effect. The damaging actions of chemical sympathectomy are reversed by administration of catecholamines while those of total adrenalectomy are reversed by cortisone. Thus, the sympathetic nervous system appears to be essential for existence at low environmental temperature. The effects of adrenalectomy can be attributed to a breakdown of sympathetic response at end-organs due to a lack of steroids.
Footnotes
- Received October 21, 1966.
- Accepted February 16, 1967.
- © 1967 by The Williams & Wilkins Company
JPET articles become freely available 12 months after publication, and remain freely available for 5 years.Non-open access articles that fall outside this five year window are available only to institutional subscribers and current ASPET members, or through the article purchase feature at the bottom of the page.
|