TY - JOUR
T1 - The importance of corticosterone in mediating restraint-induced weight loss in rats
AU - Scherer, Isabell J.
AU - Holmes, Philip V.
AU - Harris, Ruth B.S.
N1 - Funding Information:
This work was supported by NIH grant MH068281 awarded to RBSH. The authors thank Samantha Haring, Rachel Doyle and Hayden Kramer for their assistance with this project.
PY - 2011/2/1
Y1 - 2011/2/1
N2 - I. J. Scherer, P. V. Holmes, R. B.S. Harris. The importance of corticosterone in mediating restraint-induced weight loss in rats. PHYSIOL BEHAV 00 (0) 000-000, 2010. Rats restrained for 3. h/day for 3. days (RR) lose weight and do not return to the weight of non-restrained controls once restraint has ended. This study tested the importance of restraint-induced corticosterone release in mediating the change in body weight by injecting ADX rats with 2.0. mg corticosterone/kg before each restraint to replicate the restraint-induced surge in circulating corticosterone. Restrained adrenalectomized (ADX) rats injected with corticosterone had the same initial weight loss as intact restrained rats, whereas corticosterone injection in non-restrained ADX rats and restraint of ADX rats injected with saline each produced only half as much initial weight loss. Sustained weight loss, measured for 14. days after the end of RR, was the same for restrained intact rats and restrained ADX rats injected with corticosterone whereas restrained ADX rats injected with saline achieved the same weight gain as their controls. Corticosterone injections had no effect on weight gain of non-restrained intact rats. In situ hybridization showed that corticotropin releasing factor (CRF) mRNA expression in the paraventricular nucleus of the hypothalamus (PVN) was increased by the same degree in ADX rats and restrained intact rats and was not modified by corticosterone injections. There was no significant effect of restraint, ADX or corticosterone injection on PVN arginine vasopressin (AVP) mRNA expression. These data indicate that a surge in corticosterone causes sustained weight loss in ADX rats through a mechanism that can be compensated for in intact rats and is independent of changes in PVN CRF or AVP mRNA expression.
AB - I. J. Scherer, P. V. Holmes, R. B.S. Harris. The importance of corticosterone in mediating restraint-induced weight loss in rats. PHYSIOL BEHAV 00 (0) 000-000, 2010. Rats restrained for 3. h/day for 3. days (RR) lose weight and do not return to the weight of non-restrained controls once restraint has ended. This study tested the importance of restraint-induced corticosterone release in mediating the change in body weight by injecting ADX rats with 2.0. mg corticosterone/kg before each restraint to replicate the restraint-induced surge in circulating corticosterone. Restrained adrenalectomized (ADX) rats injected with corticosterone had the same initial weight loss as intact restrained rats, whereas corticosterone injection in non-restrained ADX rats and restraint of ADX rats injected with saline each produced only half as much initial weight loss. Sustained weight loss, measured for 14. days after the end of RR, was the same for restrained intact rats and restrained ADX rats injected with corticosterone whereas restrained ADX rats injected with saline achieved the same weight gain as their controls. Corticosterone injections had no effect on weight gain of non-restrained intact rats. In situ hybridization showed that corticotropin releasing factor (CRF) mRNA expression in the paraventricular nucleus of the hypothalamus (PVN) was increased by the same degree in ADX rats and restrained intact rats and was not modified by corticosterone injections. There was no significant effect of restraint, ADX or corticosterone injection on PVN arginine vasopressin (AVP) mRNA expression. These data indicate that a surge in corticosterone causes sustained weight loss in ADX rats through a mechanism that can be compensated for in intact rats and is independent of changes in PVN CRF or AVP mRNA expression.
KW - Adrenalectomy
KW - Arginine vasopressin
KW - Corticotrophin releasing factor
KW - In situ hybridization
KW - Paraventricular nucleus
UR - http://www.scopus.com/inward/record.url?scp=78649583865&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=78649583865&partnerID=8YFLogxK
U2 - 10.1016/j.physbeh.2010.11.014
DO - 10.1016/j.physbeh.2010.11.014
M3 - Article
C2 - 21092743
AN - SCOPUS:78649583865
SN - 0031-9384
VL - 102
SP - 225
EP - 233
JO - Physiology and Behavior
JF - Physiology and Behavior
IS - 2
ER -