Histidine transport in plasma membrane vesicles from rat liver.
The transport of L-histidine, a selective substrate for system N, across liver plasma membrane vesicles has been studied. The amino acid is accumulated sevenfold within the intravesicular space in the presence of a sodium gradient. Lithium can replace sodium to some extent in the cotransport mechanism. The amino acid translocation is not influenced by the transmembrane electrical potential difference. Histidine kinetics involves a saturable component plus a linear one both in the presence and in the absence of sodium. Sodium affects mainly the affinity of the translocator and to a lesser extent its mobility. Histidine uptake is competitively inhibited by glutamine and it is affected by alanine in a noncompetitive manner.
Leonardi
M G
MG
Dipartimento di Fisiologia e Biochimica Generali, Università di Milano, Italy.
Comolli
R
R
Giordana
B
B
D000409:Alanine / Q000494:pharmacology; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects* / Q000378:metabolism; D005973:Glutamine / Q000494:pharmacology; D006639:Histidine / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000201:enzymology / Q000378:metabolism*; D008297:Male; D008564:Membrane Potentials; D011188:Potassium / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D012964:Sodium / Q000378:metabolism; D013861:Thiocyanates / Q000494:pharmacology
D013861:Thiocyanates; D005973:Glutamine; D006639:Histidine; C024553:sodium thiocyanate; D012964:Sodium; D000409:Alanine; D011188:Potassium; C009941:potassium thiocyanate