L-type amino acid transporter 1 (LAT-1) and peptide transporter 2 (PEPT2) expression. A: LAT-1 expression, whole rat lung immunoblot, 50 μg protein/lane. B, left: LAT-1 expression in L2 cell lysates, 50 μg protein/lane. B, right: PEPT2 expression in L2 cell lysates, 40 μg protein/lane. C: LAT-1 (left) and PEPT2 (right) expression in rat lung.