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The effects of corticosterone on stress‐induced weight loss and corticotrophin releasing factor (CRF) mRNA expression in the paraventricular nucleus of the hypothalamus (PVN)
Author(s) -
Scherer Isabell Juliane,
Holmes Philip V,
Harris Ruth BS
Publication year - 2009
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.23.1_supplement.1021.4
Subject(s) - corticosterone , medicine , endocrinology , adrenalectomy , weight loss , hypothalamus , glucocorticoid , saline , chemistry , hormone , obesity
Rats subjected to 3 hours of restraint on 3 consecutive days (repeated restraint, RR) lose weight and do not return to the weight of non‐stressed controls (CTRL). This study tested the effect of corticosterone (CORT) on sustained weight loss by subjecting intact, adrenalectomized (ADX) and ADX with CORT replacement (ADX CORT) rats to RR. Both CTRL ADX CORT and RR ADX CORT groups were injected with 2.0 mg/kg CORT before each stress. All other rats were injected with 2.0 mL/kg saline. CORT measurements on day 2 of RR confirmed the effect of ADX and replication of stress‐induced cort in the cort injected rats. RR ADX CORT rats had the same initial and sustained weight loss as RR Intact rats. CTRL ADX CORT and RR ADX rats lost half as much weight as RR Intact rats on the days of stress and maintained the weight loss for a shorter period of time than RR Intact or RR ADX CORT rats. Thus both stress‐induced CORT and a second, undefined aspect of RR are required for the pattern of weight loss found in Intact RR rats. In a second set of rats, PVN CRF mRNA expression was increased in all ADX rats and in RR Intact rats compared with CTRL Intact rats at the end of 3 hours of restraint on the second day of restraint. CORT injections did not inhibit expression in ADX rats. This suggests that CORT contributes to initial and sustained weight loss in RR rats through a mechanism independent of PVN CRF mRNA. This study was funded by NIH grant MH06828101.