Effect of zinc deficiency on appetite and free amino acid concentrations in rat brain.
Brain amino acids were measured in 30-day-old male Long-Evans rats subsequent to feeding a 20% egg white biotin-enriched zinc-deficient diet for 9 days. The zinc-deficient (ZD) group was given distilled deionized water. Zinc-supplemented control groups included pair-fed (PF), ad libitum-fed (AL) and ad libitum-fed, overnight fasted (OF) animals. Brain tyrosine concentrations and related amino acid ratios tended to be higher when food was consumed in all groups. Brain tryptophan concentrations and a brain amino acid ratio (glycine + serine + glutamine + taurine:leucine + isoleucine + valine + methionine) were not related to food intake in ZD rats in contrast to zinc-adequate controls. Also the brain ratio of tryptophan to the sum of large neutral amino acids minus tryptophan was not related to food intake in the ZD and AL-OF groups in contrast to the PF group. There were some differences in brain amino acid concentrations between ZD rats and the control groups; however, the pattern of the brain amino acids in ZD rats did not suggest that food intake was directly influenced by them.
D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D001066:Appetite / Q000502:physiology*; D001921:Brain / Q000378:metabolism*; D004435:Eating; D008297:Male; D010649:Phenylalanine / Q000378:metabolism; D051381:Rats; D014364:Tryptophan / Q000378:metabolism; D014443:Tyrosine / Q000378:metabolism; D015032:Zinc / Q000172:deficiency*
D000596:Amino Acids; D014443:Tyrosine; D010649:Phenylalanine; D014364:Tryptophan; D015032:Zinc