the polar distribution of transport system for l-lactate in the plasma membrane of rat enterocytes -- a na+/l-lactate cotransport system in the brush-border membrane and a facilitated diffusion system in the basal-lateral membrane -- can explain the fact that in the intact epithelium l-lactate produced by cell metabolism is preferentially released on the serosal side and could enable the cell to perform vectorial , secondary active transport of l-lactate from the intestinal lumen to the serosal compartment .
C2244328
facilitated diffusion
C0007634
cell