Zarei Hamed, Kashefi Fatemeh, Hasani Keyvan
Department of Biology, CT.C., Islamic Azad University, Tehran, Iran.
Department of Basic Sciences of Veterinary Medicine, Garmsar Branch, Islamic Azad University, Garmsar, Iran.
Poult Sci. 2025 May 26;104(8):105338. doi: 10.1016/j.psj.2025.105338.
Glycinergic and adrenergic systems are integral to the regulation of meal consumption in avian species; however, the interactions between these systems have not been previously documented. This investigation was conducted to explore the interplay between the central glycinergic and adrenergic systems in regulating feed consumption among egg-type chickens. To this end, six separate experiments were performed. The first experiment involved intracerebroventricular (ICV) infusion of normal saline and glycine at different doses (50, 100, and 200 nmol) to determine its effective dose. In experiments 2-6, sub-effective doses of various adrenergic receptor antagonists-prazosin (an antagonist of α1 receptor), yohimbine (an antagonist of α2 receptor), metoprolol (an antagonist of β1 receptor), ICI 118.551 (an antagonist of β2 receptor), and SR 59230R (an antagonist of β3 receptor)-were co-administered with an effective dose of glycine to assess the potential involvement of adrenergic receptors in glycine-mediated feed intake. The cumulative feed consumption was subsequently measured at intervals of 30, 60, and 120 minutes post-administration. The findings indicated that glycine infusion at doses of 100 and 200 nmol significantly reduced meal consumption in layer chickens compared to the saline-treated control group (P < 0.05). Additionally, co-infusion of a β2 receptor antagonist attenuated the hypophagic effects typically induced by glycine (P < 0.05). However, co-administration of α1, α2, β1, and β3 receptor antagonists did not alter glycine-induced hypophagia (P ≥ 0.05). These findings suggest that the role of glycine in decreasing feed consumption in layer chickens could be facilitated by β2 adrenergic receptors.
甘氨酸能系统和肾上腺素能系统对于禽类摄食的调节至关重要；然而，此前尚未有关于这两个系统之间相互作用的记录。本研究旨在探究中枢甘氨酸能系统和肾上腺素能系统在调节蛋鸡采食量方面的相互作用。为此，进行了六个独立实验。第一个实验通过脑室内（ICV）注射不同剂量（50、100和200纳摩尔）的生理盐水和甘氨酸来确定其有效剂量。在实验2 - 6中，将各种肾上腺素能受体拮抗剂——哌唑嗪（α1受体拮抗剂）、育亨宾（α2受体拮抗剂）、美托洛尔（β1受体拮抗剂）、ICI 118.551（β2受体拮抗剂）和SR 59230R（β3受体拮抗剂）的亚有效剂量与有效剂量的甘氨酸共同给药，以评估肾上腺素能受体在甘氨酸介导的采食量中的潜在作用。随后在给药后30、60和120分钟的间隔时间测量累积采食量。结果表明，与生理盐水处理的对照组相比，100和200纳摩尔剂量的甘氨酸注射显著降低了蛋鸡的采食量（P < 0.05）。此外，β2受体拮抗剂的共同注射减弱了通常由甘氨酸诱导的摄食减少效应（P < 0.05）。然而，α1、α2、β1和β3受体拮抗剂的共同给药并未改变甘氨酸诱导的摄食减少（P≥0.05）。这些发现表明，β2肾上腺素能受体可能有助于甘氨酸在降低蛋鸡采食量方面的作用。
