Ghrelin-induced hypophagia is mediated by the β2 adrenergic receptor in chicken

Abstract

The purpose of this study was to examine the effects of intracerebroventricular injection of metoprolol (a β1 adrenergic receptor antagonist), ICI 118,551 (a β2 adrenergic receptor antagonist), and SR 59230R (a β3 adrenergic receptor antagonist) on ghrelin-induced food and water intake by 3-h food-deprived (FD3) cockerels. The chickens were randomly allocated to 4 treatment groups with 8 replicates in each group. A cannula was surgically implanted into the lateral ventricle of the brain. In experiment 1, chickens received the β1 adrenergic receptor antagonist (24 nmol) before injection of the ghrelin (0.6 nmol). In experiment 2, chickens received the β2 adrenergic receptor antagonist (5 nmol) before injection of the ghrelin (0.6 nmol). In experiment 3, birds were injected with ghrelin (0.6 nmol) after the β3 adrenergic receptor antagonist (20 nmol). Cumulative food and water intake were recorded 3-h post injection and analyzed by two-way analysis of variance. According to the results, ghrelin injection reduced food and water intake by broiler cockerels (p≤0.05). The effect of ghrelin on food intake was significantly attenuated by pretreatment with the β2 receptor antagonist (p≤0.05). Furthermore, the β2 receptor antagonist had no effect on water intake induced by ghrelin. Also, pretreatment with the β1 and β3 receptors antagonists had no effect on ghrelin-induced food and water intake. These results suggest that the effect of ghrelin on cumulative food intake by cockerels is mediated via β2 adrenergic receptors.

The role of cyclooxygenase inhibitors in lipopolysaccharide-induced hypophagia in chicken

“…Also, administration of NPY increases feed intake by both broiler and layer chickens. Genetic selection for meat or egg production presumably genetically altered in central neurological pathways associated with food-intake control mechanisms (Zendehdel and Hassanpour 2014). Because of the lack of investigations on the possibility of LPS and COX effect on food intake in avian, the major finding in our study is that presumably COX-2 doi: 10.17221/8403-CJAS mediates LPS-induced hypophagia in broilers.…”

Possible Involvement of Beta-Adrenergic Receptors on Nociceptin/Orphanin FQ Induced Food Consumption in Male Rats

“…It is well known that the direct isoprotrenol-induced activation of adrenergic fibers in the brainstem is paralleled by an inhibitory synaptic effect on α-melanocyte stimulating hormone neurons of the ventrolateral arcuate nucleus [19]. The central orexigenic effect of N/OFQ in rats is not well understood but recent studies suggest that N/OFQ increases food consumption in a manner similar to GABA receptors and opioid peptides [20]. Furthermore, both beta-adrenergic and N/OFQ receptors, has been shown to exist in various regions of the brain [21,22].…”

Involvement of Gaba and Cannabinoid Receptors in Central Food Intake Regulation in Neonatal Layer Chicks: Role of CB1 and Gabaa Receptors

“…There is central evidence mechanisms for food intake regulation are different between mammalian and birds (Zendehdel & Hassanpour 2014). Comparative physiological studies suggested there are differences award pathways between the meat-type and layertype chicks (Alizadeh et al, 2015).…”

“…In the central nervous system (CNS), several neurotransmitters interact by a wide distributed neurological network on food intake regulation (Zendehdel et al, 2014;Honda, 2016). γ-aminobutyric acid (GABA) is one of the most abundant neurotransmitter in mammalian brain.…”