Investigation of Synergistic Effects of Corticotropin and Melanocortin receptors with Sub-Effective Dose of Phoenixin-14 on Food Intake in Neonatal Chickens

Various peptides are involved in food intake regulation in the bird and mammalian brain. Melanocortin and corticotropin play an important role in food intake control. On the other hand, phoenixin-14 increases food intake. This study aimed to investigate the synergistic effects of corticotropin and melanocortin with a sub-effective dose of phoenix -14 on food intake in neonatal chickens.

A total of one hundred and ninety-two neonatal chicks were randomly divided into three experimental groups. Each experiment had a control group and three treatment groups (n=12 in each group). In all experiments, 3-hours food-deprived birds received intracerebroventricular ‎injections of either control diluent or drug solution. Then the birds had ad libitum access to the ‎food and fresh water, and then cumulative food intake (gr) was measured based on the ‎percentage of the body. In the first experiment, control solution, phoenixin-14 (0.8 nmol), Astressin-B (CRF1/CRF2 receptor antagonist; 30 µg), and phoenixin-14 + Astressin-B were injected. ‎  In the second experiment, control solution, phoenixin-14, Astressin-2B (CRF2 receptor antagonist; 30 µg), and phoenixin-14 + Astressin-2B were injected. In the third experiment, control solution, phoenixin-14 (0.8 nmol), SHU9119 (MC3/MC4 receptor antagonist; 0.5 nmol), and phoenixin-14 + SHU9119 were injected. In the fourth experiment, control solution, phoenixin-14 (0.8 nmol), MCL0020 (MC4 receptor antagonist; 0.5 nmol), and phoenixin-14 + MCL0020 were injected.

The results showed that co-inject ion of phoenixin-14 + Astressin-B and phoenixin-14 + Astressin-2B significantly increased food intake(p<0.05), while co-injection of phoenixin-14 + SHU9119 and phoenixin-14 + MCL0020 had no effect(p>0.05).

According to the results of the present study, there is probably a synergistic effect between phoenixin-14 and corticotropin system on food intake control of neonatal chicks.