Interaction of neuropeptide Y receptors (NPY₁, NPY₂ and NPY₅) with somatostatin on somatostatin-induced feeding behaviour in neonatal chicken

ABSTRACT

1. The present study was conducted to investigate whether brain somatostatin increases feed intake in neonatal chickens. The mediating role of neuropeptide Y receptors on feed intake induced by somatostatin was investigated.

2. In this study, seven experiments were designed, each with four treatment groups (n = 44 in each experiment). In Experiment 1, chicks received control solution and 0.5, 1 and 2 nmol of somatostatin through intracerebroventricular (ICV) injection. In experiments 2, 3 and 4, chickens were ICV injected with control solution and 1.25, 2.5 and 5 μg of B5063 (NPY₁ receptor antagonist), SF22 (NPY₂ receptor antagonist) and SML0891 (NPY₅ receptor antagonist), respectively. In experiment 5, 6 and 7 chickens received ICV injection of B5063, SF22, SML0891, with a co-injection of + somatostatin, control solution and somatostatin. The cumulative feed intake was measured until 120 min post injection.

3. Somatostatin significantly increased feed intake in FD3 chicks. Both B5063 and SML0891 dose-dependently decreased feed intake compared with the control group, while SF22 led to a dose-dependent increase in feed intake. In addition, the hyperphagic effect of somatostatin significantly decreased with co-injection of B560 plus somatostatin (p < 0.05), but SF22 and SML0891 had no effect on feed intake induced by somatostatin in chicks (p > 0.05).

4. Based on the results of this study, it is likely that somatostatin increased feed intake and NPY₁ receptor acts as a mediator in hyperphagic effect of somatostatin in neonatal chicks.

KEYWORDS:

• Feed intake
• ICV injection
• neonatal chicks
• NPY receptor’s antagonists
• somatostatin

Acknowledgments

The authors thank the central laboratory (Dr. Rastegar Lab.) of the Faculty of Veterinary Medicine, University of Tehran for cooperation. This research is conducted as a part of the PhD thesis of the first author.

Disclosure statement

No potential conflict of interest was reported by the authors.

Informed Consent

This manuscript does not contain any studies with human subjects performed by any of the authors.

Human and Animal Rights

All experiments were executed according to the Guide for the Care and Use of Laboratory Animals and were approved by the institutional animal ethics committee.

Additional information

Funding

This work was supported by the Ferdowsi University of Mashhad [Grant no. 3/40151].