Catecholamine response to stress: age related modifications in tail-suspended rats.
The catecholamine response to acute stress has been shown to change with age. However, alterations under chronic stress conditions have not been established. This study attempted to determine whether aging modifies the catecholamine response to chronic stress load in rats subjected to tail suspension. Urinary excretions of epinephrine (E) and norepinephrine (NE) were monitored before and during the tail suspension experiments in rats at two different ages: 5 weeks old (young) and 18 months old (aged). Basal excretions of E and NE before the suspension were higher in the aged rats, indicating that sympathetic-adrenal medullary activities increase with age under resting conditions. The chronic stress load elicited E responses in the aged rats similar to those in the young rats. The NE responses, however, were completely different in that tail suspension caused a greater increase in NE excretion in the young rats than in the aged rats. This finding suggests that the sympathetic response to chronic stress load changes with age.
Kawano
S
S
Department of Endocrinology and Metabolism, Division of Molecular and Cellular Adaptation, Research Institute of Environmental Medicine, Nagoya University.
Ohmori
S
S
Kambe
F
F
Kanda
K
K
Murata
Y
Y
Seo
H
H
D000311:Adrenal Glands / Q000378:metabolism / Q000502:physiology; D000375:Aging / Q000502:physiology*; D000818:Animals; D001835:Body Weight; D004837:Epinephrine / Q000378:metabolism* / Q000652:urine; D019417:Hindlimb Suspension; D008297:Male; D009638:Norepinephrine / Q000378:metabolism* / Q000652:urine; D051381:Rats; D017208:Rats, Wistar; D013312:Stress, Physiological / Q000378:metabolism* / Q000652:urine; D013564:Sympathetic Nervous System / Q000378:metabolism / Q000502:physiology; D015431:Weight Loss; D018474:Weightlessness Simulation
D009638:Norepinephrine; D004837:Epinephrine