Half-life of Fructosyl-valine in the Plasma of Chicks

Eighty 14-d-old single-comb White Leghorn male chicks were divided into 16 groups with five birds each. Fructosyl-valine, which is a valine-glucose-Amadori product, was intravenously (2,250 nmol/kg body weight) or orally (300 µmol/kg body weight) administered to chicks. Blood samples were collected 15, 30, 60, 120, 180, 360, 720 and 1440 min after administration. Plasma concentrations of fructosyl-valine were measured by using a liquid chromatography / mass spectrometry (LC/MS). The time course change in plasma fructosyl-valine concentration showed an exponential curve, as y=a+be^-. The half-life of plasma fructosyl-valine was calculated by the following equation: (log_e2)/λ. When fructosyl-valine was injected intravenously, the highest value for plasma fructosyl-valine concentration was observed 15 min after administration. When injected intravenously, the half-life of plasma fructosyl-valine was calculated to be 231 min. When fructosyl-valine was administered orally to chicks, the highest value for plasma fructosyl-valine concentration was observed 180 min after administration. When administered orally, the half-life of plasma fructosyl-valine was calculated to be 277 min. We conclude that the half-life of fructosyl-valine in plasma was approximately 4 h, which is longer than that of glycated tryptophan.