Free Tyrosine Levels of Rat Brain and Tissues with Sympathetic Innervation following Administration of l-Tyrosine in the Presence and Absence of Large Neutral Amino Acids

摘要: The tyrosine concentration of fasted rats was measured in plasma, brain and tissues receiving sympathetic innervation after L-tyrosine (200 mg/kg) administered alone or the presence an equimolar cocktail containing isoleucine, leucine valine. In samples taken at 15, 30, 45, 60, 120 180 minutes, highest concentrations were observed heart, adrenal gland kidney 15 but interscapular brown adipose tissue 30 minutes 15-60 minutes. decline from peak slower brain, than all examined, control levels free attained by postadministration . Competing large neutral amino acids reduced maximal uptake 48% had no effect other examined.