|
|
||||||||
AJP - Endocrinology and Metabolism, Vol 240, Issue 3 314-E319, Copyright © 1981 by American Physiological Society
ARTICLES |
J. B. Young and L. Landsberg
Fasting decreases and cold exposure increases sympathetic nervous system activity. The present studies examine the effect of fasting and cold together on sympathoadrenal function. At 4 degrees C animals fasted for 2 days excreted 29% less norepinephrine (NE) than fed animals, averaging 458 +/- 32ng NE/mg creatinine and 646 +/- 68, respectively (P less than 0.005), but 122% more epinephrine (E) 77.9 +/- 11.7 ng E/mg creatinine and 35.1 +/- 6.7, respectively (P less than .01). Fasting for 2 days reduced cardiac NE turnover, a direct measure of sympathetic neuronal activity, 33% in animals at 22 degrees C from 28.2 +/- 3.6 ng NE . heart-1 . h-1 to 18.9 +/- 4.8 (95% confidence intervals) and 25% in animals acutely exposed to 4 degrees C from 60.7 +/- 8.0 to 45.6 +/- 9.5. Similar reductions in urinary NE excretion and cardiac NE turnover were observed in adrenal-demedullated rats. Thus fasting at 4 degrees C lowers sympathetic activity and enhances adrenal medullary secretion. This pattern of decreased sympathetic and increased adrenal medullary activity, previously seen with fasting hypoglycemia, suggests an important role for the adrenal medulla in internal homeostasis at times when the sympathetic nervous system is suppressed.
This article has been cited by other articles:
![]() |
N. A. Brito, M. N. Brito, and T. J. Bartness Differential sympathetic drive to adipose tissues after food deprivation, cold exposure or glucoprivation Am J Physiol Regulatory Integrative Comp Physiol, May 1, 2008; 294(5): R1445 - R1452. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. F. Morrison Differential control of sympathetic outflow Am J Physiol Regulatory Integrative Comp Physiol, September 1, 2001; 281(3): R683 - R698. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. B. Chambers, T. D. Williams, A. Nakamura, R. P. Henderson, J. M. Overton, and M. E. Rashotte Cardiovascular and metabolic responses of hypertensive and normotensive rats to one week of cold exposure Am J Physiol Regulatory Integrative Comp Physiol, October 1, 2000; 279(4): R1486 - R1494. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |