Correlation of Histamine Receptors and Adrenergic Receptor in Broilers Appetite

The current study was conducted to investigate the interaction between the central adrenergic and histaminergic systems and the broiler chick’s feed intake. In the first experiment, the intracerebroventricular (ICV) injection of solutions was conducted which included ۱۰ nmol of prazosin (an α۱-receptor antagonist), ۳۰۰ nmol of histamine, co-injection of prazosin and histamine. Experiments two to five were conducted similarly the same as the first experiment, in which chickens were ICV injected with ۱۳ nmol of yohimbine (an α۲-receptor antagonist), ۲۴ nmol of metoprolol (a β۱ adrenergic receptor antagonist), ۵ nmol of ICI ۱۱۸,۵۵۱ (a β۲ adrenergic receptor antagonist), and ۲۰ nmol of SR ۵۹۲۳۰R (a β۳ adrenergic receptor antagonist). The injected solutions in the sixth experiment included ۳۰۰ nmol of noradrenaline, ۲۵۰ nmol of α-FMH (an alpha fluoromethyl histidine), noradrenaline, and α-FMH. Seventh to ninth experiments were similar to the sixth experiment, except that the chickens were ICV injected with ۳۰۰ nmol of chlorpheniramine (a histamine H۱ receptors antagonist), ۸۲ nmol of famotidine (a histamine H۲ receptors antagonist), and ۳۰۰ nmol of thioperamide (a histamine H۳ receptors antagonist), rather than α-FMH. Afterward, the cumulative food intake was measured ۱۲۰ min after injection. Based on the obtained results, both histamine ICV injection and noradrenaline injection reduced food intake (P<۰.۰۵). Moreover, co-injection of histamine and ICI ۱۱۸,۵۵۱ (P<۰.۰۵), and co-injection of noradrenaline and Chlorpheniramine reduced food intake (P<۰.۰۵). In addition, noradrenaline and Thioperamide co-injection improved hypophagic effect of noradrenaline in neonatal chicken (P<۰.۰۵). These findings suggested the effect of interconnection between adrenergic and histaminergic systems, which may be mediated by H۱ and H۳ histaminergic and β۲ adrenergic receptors, on the regulation of food intake in the neonatal broiler chicken.

Keywords:

Adrenergic , Broiler chicken , Food intake , Histamine