Affiliation:
1. Razi University
2. Islamic Azad University
Abstract
Abstract
Background
Adrenomedullin has various physiological roles including appetite regulation. The objective of present study was to determine the effects of intracerebroventricular injection of adrenomedullin and its interaction with NPY and CCK receptors on food intake regulation in layer-type chicks. In experiment 1, chickens received ICV injection of saline and adrenomedullin (1, 2 and 3 nmol). In experiment 2, birds injected with saline, B5063 (NPY1 receptor antagonist, 1.25 µg), adrenomedullin (3 nmol) and co-injection of B5063 + adrenomedullin. Experiments 3–5 were similar to experiment 2 and only SF22 (NPY2 receptor antagonist, 1.25 µg), SML0891 (NPY5 receptor antagonist, 1.25 µg) and CCK4 (1 nmol) were injected instead of B5063. In experiment 6, ICV injection of saline and CCK8s (0.125, 0.25 and 0.5 nmol) were done. In experiment 7, chickens injected with saline, CCK8s (0.125 nmol), adrenomedullin (3 nmol) and co-injection of CCK8s + adrenomedullin. After the ICV injection, birds were returned to their individual cages immediately and cumulative food intake was measured at 30, 60 and 120 min after injection.
Results
According to the results, adrenomedullin (2 and 3 nmol) decreased food intake compared to control group (P < 0.05). Co-injection of the adrenomedullin + B5063 amplified hypophagic effect of adrenomedullin (P < 0.05). The ICV injection of the CCK8s (0.25 and 0.5 nmol) reduced food intake (P < 0.05). Co-injection of the CCK8s + adrenomedullin significantly potentiated adrenomedullin-induced hypophagia (P < 0.05). Nevertheless, administration of the SF22, SML0891 and CCK4 had no effect on the anorexigenic response evoked by adrenomedullin in chickens (P > 0.05).
Conclusion
These results suggested that the hypophagic effect of the adrenomedullin is mediated by NPY1 and CCK8s receptors. However, our novel results should form the basis for future experiments.
Publisher
Research Square Platform LLC