Vasopressin, corticotrophin-releasing factor, and pituitary adrenal responses to acute cold stress in normal humans.
Acute cold stress is a consistent stimulus to ACTH secretion in rats yet inhibits arginine vasopressin (AVP) in both rats and humans. We have studied the interrelationships of AVP, corticotrophin-releasing factor, and atrial natriuretic factor (ANF) in the hypothalamo-pituitary-adrenal response to acute cold stress in normal humans. Six healthy male volunteers deprived of food and fluid for 6 h, and minimally clothed, were studied in the early afternoon. After a 30-min period at 22 C, subjects were exposed to cold stress (4 C for 30 min), followed by a 30-min equilibration period at 22 C. By the end of the period of cold exposure there was a fall in plasma volume of 7.8 +/- 1.4% (mean +/- SEM), a significant increase in both systolic blood pressure (P = 0.0001) and in plasma norepinephrine level (P = 0.0001), but no change in plasma epinephrine or in plasma ANF. Plasma AVP levels fell significantly (P less than 0.01) to reach a nadir at 5-10 min after cold exposure before returning to baseline levels. A significant fall in plasma cortisol levels occurred during the first 15 min of the baseline period and remained stable thereafter. No significant changes in plasma corticotrophin-releasing factor or ACTH occurred. These results suggest that cold inhibition of AVP release, presumably via afferent baroreceptor pathways, may act to reduce the response of the corticotrophs to a potentially noxious stimulus. Inhibition of AVP and/or ACTH during acute cold exposure are not dependent upon an increase in plasma ANF.
Wittert
G A
GA
Department of Endocrinology, Princess Margaret Hospital, Christchurch, New Zealand.
Or
H K
HK
Livesey
J H
JH
Richards
A M
AM
Donald
R A
RA
Espiner
E A
EA
D000208:Acute Disease; D000328:Adult; D001127:Arginine Vasopressin / Q000097:blood*; D001794:Blood Pressure; D003080:Cold Temperature; D003346:Corticotropin-Releasing Hormone / Q000097:blood*; D006801:Humans; D008297:Male; D010913:Pituitary-Adrenal System / Q000503:physiopathology*; D011188:Potassium / Q000097:blood; D011388:Prolactin / Q000097:blood; D012016:Reference Values; D012083:Renin / Q000097:blood; D012964:Sodium / Q000097:blood; D013312:Stress, Physiological / Q000097:blood / Q000209:etiology / Q000503:physiopathology*
D001127:Arginine Vasopressin; D011388:Prolactin; D003346:Corticotropin-Releasing Hormone; D012964:Sodium; D012083:Renin; D011188:Potassium