The central corticotropin-releasing factor and glucagon-like peptide-1 in food intake of the neonatal chick.

Recently, we have reported that central administration of glucagon-like peptide-1 (GLP-1) strongly decreases food intake of chicks. The aim of this study was to elucidate whether suppressed food intake induced by the central injection of GLP-1 is mediated by activation of the hypothalamic-pituitary-adrenal axis. First, the effects of central administration of corticotropin-releasing factor (CRF) were investigated. Birds (2-day-old) were food-deprived for 3 h and then CRF or saline was injected intracerebroventricular (i.c.v.). CRF strongly inhibited food intake. Thereafter, effects of central CRF or GLP-1 on plasma corticosterone concentration were examined. CRF significantly stimulated corticosterone release, but GLP-1 did not alter plasma corticosterone concentration. These results suggest that CRF is a potent inhibitor of food intake in the chick, but the suppression of food intake induced by central GLP-1 may not be involved in the activation of hypothalamic-pituitary-adrenal axis.