Department of Basic Sciences, Faculty of Veterinary Medicine, Science and Research Branch, Islamic Azad University, Tehran, Iran.
Department of Basic Sciences, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.
Arch Razi Inst. 2021 Jul;76(2):345-358. doi: 10.22092/ari.2020.341240.1425. Epub 2021 Jul 1.
Central dopaminergic (DAergic) and adrenergic systems have a prominent role in appetite regulation; however, their interaction(s) have not been studied in neonatal layer chickens.Therefore, the current study aimed to determine the interaction of central DAergic and noradrenergic systems in food intake regulation in neonatal layer chickens. In the first experiment, chickens received the intracerebroventricular (ICV) injection of a control solution, prazosin (i.e., α1 adrenergic receptor antagonist; 10 nmol), dopamine (DA; 40 nmol), and prazosin plus DA. The second to fifth experiments were similar to the first experiment except that the birds were injected with yohimbine (i.e., α2 receptor antagonist; 13 nmol), metoprolol (i.e., β1 adrenergic receptor antagonist; 24 nmol), ICI 118,551 (i.e., β2 adrenergic receptor antagonist; 5 nmol), and SR59230R (i.e., β3 adrenergic receptor antagonist; 20 nmol) instead of prazosin. In the sixth experiment, the chickens received ICV injection with the control solution and noradrenaline (NA; 75, 150, and 300 nmol). In the seventh experiment, the birds were injected with the control solution, SCH23390 (i.e., D1 DAergic receptor antagonist; 5 nmol), NA (300 nmol), and SCH23390 plus NA In the eighth experiment, the control solution, AMI-193 (i.e., D2 DAergic receptor antagonist; 5 nmol), NA (300 nmol), and AMI-193 plus NA were injected. Then, cumulative food intake was recorded at 30, 60, and 120 min after the injection. According to the obtained results, the ICV injection of DA (40 nmol) significantly decreased food intake in comparison to that reported for the control group (p <0.05). The co-injection of yohimbine plus DA significantly amplified DA-induced hypophagia in the neonatal chickens (p <0.05). In addition, the co-administration of ICI 118,551 plus DA significantly inhibited the hypophagic effect of DA in the neonatal chickens (p <0.05). Furthermore, NA (75, 150, and 300 nmol) significantly reduced food intake in a dose-dependent manner (p <0.05). The co-injection of SCH23390 plus NA decreased the hypophagic effect of NA in the neonatal chickens, compared to that reported for the control group (p <0.05). The co-injection of AMI-193 plus NA diminished NA-induced hypophagia, compared to that reported for the control group (p <0.05). The aforementioned results suggested that there is an interconnection between central DAergic and noradrenergic systems through α2/β2 adrenergic and D1/D2 DAergic receptors in food intake regulation in neonatal chicks.
中枢多巴胺（DAergic）和肾上腺素能系统在食欲调节中起着重要作用；然而，它们之间的相互作用尚未在新生层鸡中进行研究。因此，本研究旨在确定中枢 DAergic 和去甲肾上腺素能系统在新生层鸡的食物摄入调节中的相互作用。在第一个实验中，鸡接受了脑室内（ICV）注射对照溶液、哌唑嗪（即 α1 肾上腺素能受体拮抗剂；10 nmol）、多巴胺（DA；40 nmol）和哌唑嗪加 DA。第二至第五个实验与第一个实验相似，只是鸡被注射了育亨宾（即 α2 受体拮抗剂；13 nmol）、美托洛尔（即 β1 肾上腺素能受体拮抗剂；24 nmol）、ICI 118,551（即 β2 肾上腺素能受体拮抗剂；5 nmol）和 SR59230R（即 β3 肾上腺素能受体拮抗剂；20 nmol）而不是哌唑嗪。在第六个实验中，鸡接受了 ICV 注射对照溶液和去甲肾上腺素（NA；75、150 和 300 nmol）。在第七个实验中，鸡接受了对照溶液、SCH23390（即 D1 DAergic 受体拮抗剂；5 nmol）、NA（300 nmol）和 SCH23390 加 NA 的注射。在第八个实验中，鸡接受了对照溶液、AMI-193（即 D2 DAergic 受体拮抗剂；5 nmol）、NA（300 nmol）和 AMI-193 加 NA 的注射。然后，在注射后 30、60 和 120 分钟记录累积食物摄入量。根据获得的结果，与对照组相比，DA（40 nmol）的 ICV 注射显著降低了食物摄入量（p <0.05）。育亨宾加 DA 的共同注射显著增强了新生鸡中 DA 诱导的食欲减退（p <0.05）。此外，ICI 118,551 加 DA 的共同给药显著抑制了 DA 对新生鸡的食欲减退作用（p <0.05）。此外，NA（75、150 和 300 nmol）以剂量依赖性方式显著减少食物摄入量（p <0.05）。SCH23390 加 NA 的共同注射降低了 NA 对新生鸡的食欲减退作用，与对照组相比（p <0.05）。AMI-193 加 NA 的共同注射减弱了 NA 诱导的食欲减退，与对照组相比（p <0.05）。上述结果表明，在新生小鸡的食物摄入调节中，中枢 DAergic 和去甲肾上腺素能系统之间存在通过 α2/β2 肾上腺素能和 D1/D2 DAergic 受体的相互联系。
