Cationic amino acid transport in chicken small intestine

1. The cationic amino acids have been shown to represent a transport class in the chicken small intestine on the basis of their competition for what appears to be a single transport site. 2. This site does not appear to be the primary site of histidine entry. 3. Leucine is a strong competitive inhibitor of arginine uptake, while the influence of arginine upon the influx of leucine is slight. 4. Comparison of inhibition of lysine and methionine by various amino acids and analogs showed that the inhibition of lysine by neutral amino acids occurs by their attachment to a site other than the one involved in the uptake of methionine.