The characteristic changes of amino acid transport during development in brush border membrane vesicles of the guinea pig ileum.
The characteristic changes of transport systems for amino acids during development were studied with brush border membrane vesicles from the guinea pig ileum. There was a difference of Km value for L-proline transport kinetics between the vesicles on the 10th day after birth and those on the 60th day after birth. Differences of fatty acid composition of phospholipids and unsaturated percentage of fatty acids were observed between these two vesicles. Fluorescence polarization of the vesicles on the 10th day after birth was larger than that of the vesicles on the 60th day after birth at each temperature examined. L-Proline transport at a substrate concentration below Km was larger in the vesicles on the 60th day after birth than in the vesicles on the 10th day after birth at each corresponding temperature. Differences of L-leucine transport characteristics were not observed between these two vesicles. These results suggest that the characteristic changes of L-proline and L-leucine transports during development are different and the characteristics of L-proline transport are regulated at least in part by membrane fluidity which is controlled by membrane lipid composition.
D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D001692:Biological Transport; D006168:Guinea Pigs; D007082:Ileum / Q000378:metabolism / Q000648:ultrastructure*; D007700:Kinetics; D007930:Leucine / Q000378:metabolism; D008560:Membrane Fluidity; D008563:Membrane Lipids / Q000032:analysis; D008871:Microvilli / Q000378:metabolism; D011392:Proline / Q000378:metabolism; D013997:Time Factors
D000596:Amino Acids; D008563:Membrane Lipids; D011392:Proline; D007930:Leucine