The avian central roles of alpha and beta oestrogen receptors on food intake.

In rodents, oestrogen reduces food intake centrally via alpha oestrogen receptors (αER). As there was no report about the central roles of oestrogen receptors of alpha and beta, on food intake behaviour in birds, we aimed at this subject. In the first experiment beta oestradiol, a specific beta oestrogen receptor (βER; 0, 2.5, 5,10, 15 and 31 μg) was injected intracerebroventricularly (ICV) to 3-h fasted broilers. The second and third experiments were similar to the first one, but alpha oestradiol, the specific (αER; 2.5, 5 and 10 μg) and MPP hydrochloride, a highly selective antagonist of (αER) (0.1, 1 and 10 μg) were used. Our result showed that alpha oestradiol increased food intake and MPP hydrochloride reversed this effect. This study shows that, similar to rodents, in the avian brain (aER) are involved in food intake behavior, but despite them, their effects are stimulatory.