Non-essential amino acids and short-term food intake of rats

Abstract

The objective of these studies was to evaluate the role of the six non- essential amino acids (NEAA) found in egg albumin, either in groups or individually on food intake of rats fed a 25% casein defined diet. Compared to control (water), 1.5g of a complete NEAA mixture given by gavage caused significant suppression in food intake by 70, 75 and 18% during the 1st, 2nd and 12th hour of feeding. Asp+Glu in the amount (0.79g) found in the mixture caused feeding suppression by 39, 33 and 12.3%, respectively, (p<0.05), whereas Ala, Gly, Pro and Ser (0.71g) reduced feeding only during the 1st hour of feeding by 40% (p<0.05). After Ala+Pro (0.35g), rats ate 30% less (p<0.05) in the 1st hour but exhibited a rebound in appetite in the 2nd hour (+71%, p<0.05). Food intake of rats given Gly+Ser (0.36g) was suppressed by 20% (p<0.05) only in the 1st hour of feeding. When given alone, only Glu (0.43g), Gly (0.12g) and Ser (0.24g) suppressed appetite, primarily in the 1st hour of feeding. Overall, food intake suppression in the 1st hour was significantly correlated with the quantity of amino acid gavaged (r=0.9, p<0.01) but the possibility that structural or metabolic features of the individual amino acids may play a role in the feeding response was not excluded.