In vitro uptake of vitamin A from the retinol-binding plasma protein to mucosal epithelial cells from the monkey's small intestine.

摘要: The in vitro uptake of retinol from its plasma carrier protein, the retinol-binding protein (RBP), to cells monkey's small intestine has been studied. [3H]Retinol was readily delivered RBP without a concomitant cellular RBP. [3H]retinol accumulation dependent on temperature and virtually abolished at 0 degrees. Several metabolic inhibitors could not impede process. linear for about 45 min exhibited characteristic saturation kinetics. by be inhibited containing unlabeled retinol, vitamin A-depleted RBP, Fab' fragments against In contrast, free, metabolite form lacking affinity prealbumin, were inactive. It is therefore suggested that there receptor A cell surface which recognizes part protein-ligand complex.