Intracerebroventricularly administered phenylalanine and tyrosine: Effects on feeding behavior and norepinephrine concentrations Of specific brain sites in the chicken

A study was carried out to investigate the action of central L-phenylalanine (Phe) and L-tyrosine (Tyr) on food intake of the chicken. In the first trial, Phe (200 μg/10 μl) or saline was acutely administered into the right lateral ventricle (i.c. v.) of chickens (5 birds per each group). Birds (4 birds per each group) were administered with the i.c.v. Tyr (200 μg/10 μl) or saline in the second trial. The brains of the birds were removed for catecholamine assay 30 min postadministration. Catecholamine concentrations were measured at specific sites of the brain (LH: lateral hypothalamus, PVN: paraventricular nucleus, and VMH: ventromedial hypothalamus). No significant effect of amino acids on the concentration of norepinephrine of brain sites investigated was detected. Food intake and rectal body temperature were also monitored for 6 h after central administrations of Phe, Tyr or saline (5 birds per each group). Both Phe and Tyr, up to 1 mg/10 μl, failed to modulate food intake or rectal body temperature.