抄録
Intestinal uptake of riboflavin was studied kinetically in details by using everted intestinal rings of rats. In ^<14>C-riboflavin uptake to intestinal rings, two mechanisms were proved; the linear component due to diffusion and the saturable component which predominates at concentrations less than 0.5μM and is against concentration gradients. By the Lineweaver-Burk plots, K_m values and V_<max> were shown to be 0.13 μM and 0.55 nmol/g tissue/15 min. The saturable component was influenced by additions of metabolic inhibitors such as 2,4-dinitrophenol, KCN, and NaF, but the linear component was not. Neither of the two components were inhibited by ouabain. The uptake in the linear component were enhanced by bile salt (taurocholate) and Tween 80, but those of the saturable component were not.
