Effects of intracerebroventricular injection of spexin and its interaction with NPY, GalR2 and GalR3 receptors on the central food intake regulation and nutritional behavior in broiler chickens

The effect of spexin injection and its interaction with nitric oxide, serotonin, and corticotropin receptors on the central regulation of food intake in broilers

“…(Sigma, USA) ( Jonaidi et al, 2012 ; Motaghi et al, 2022 ; Yousefi et al, 2019 ). The effective dose for spexin in neonatal broilers was obtained from our recently published study ( Farzin et al, 2022 ).…”

Recent Research on Mechanisms of Feeding Regulation in Chicks

“…Generally, fasting upregulates orexigenic factors and downregulates anorexigenic factors; for example, the expressions of orexigenic neuropeptides such as neuropeptide Y (NPY) and agouti-related peptide (AgRP) are significantly increased by fasting in chicken hypothalamus[ 37 , 38 ], whereas fasting significantly decreases those of proopiomelanocortin (POMC, the precursor of α-melanocyte stimulating hormone (α-MSH), an anorexigenic peptide) in the hypothalamus and gut hormone such as cholecystokinin (CCK) and peptide YY in chicken gastrointestinal tract[ 37 , 38 , 39 , 40 ]. However, intracerebroventricular (ICV) and intravenous injections of SPXs significantly decrease food intake in a dose-dependent manner in chicks[ 35 , 36 , 41 ], in contrast to GAL, an orexigenic peptide in vertebrates[ 24 ]. The decrease following ICV injection of SPX is attenuated by the co-injection of GALR3 antagonists, but not GALR2 antagonists, suggesting that SPX inhibits food intake via GALR3 in chicks[ 41 ].…”

“…However, intracerebroventricular (ICV) and intravenous injections of SPXs significantly decrease food intake in a dose-dependent manner in chicks[ 35 , 36 , 41 ], in contrast to GAL, an orexigenic peptide in vertebrates[ 24 ]. The decrease following ICV injection of SPX is attenuated by the co-injection of GALR3 antagonists, but not GALR2 antagonists, suggesting that SPX inhibits food intake via GALR3 in chicks[ 41 ]. Furthermore, SPXs control food intake via the gene expression of appetite-regulating neuropeptides in the hypothalamus of chicks[ 35 , 36 ].…”

Central regulation of appetite in birds: Recent advances and future perspective

“…The results of another research show the role of SPX in the leptin's action on POMC gene expression in the hypothalamus which affects the hypophagic effects of leptin (84). Despite the limitations of experiments conducted on birds, Farzin et al's (2022, 2023) studies showed that SPX-induced anorexia could be mediated via nitric oxide (NO), 5-HT2C, NPY1, GalR3, CRF1, and CRF2 receptors in meat-type chickens (85,86). Future perspective…”