Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
CHARACTERIZATION OF NA-INDEPENDENT GLUTAMINE TRANSPORT IN RAT-LIVER()
Autore:
PACITTI AJ; INOUE Y; SOUBA WW;
Indirizzi:
MASSACHUSETTS GEN HOSP,DEPT SURG BOSTON MA 02114 UNIV FLORIDA,COLL MED,DEPT SURG GAINESVILLE FL 32610
Titolo Testata:
The American journal of physiology
fascicolo: 1, volume: 265, anno: 1993,
parte:, 1
pagine: 70000090 - 70000098
SICI:
0002-9513(1993)265:1<70000090:CONGTI>2.0.ZU;2-P
Fonte:
ISI
Lingua:
ENG
Soggetto:
AMINO-ACID-TRANSPORT; PLASMA-MEMBRANE VESICLES; MOUSE BLASTOCYSTS; CELL-LINES; SYSTEM-L; HEPATOCYTES; ERYTHROCYTES; METABOLISM;
Keywords:
AMINO ACID TRANSPORT; HEPATOCYTE; MEMBRANE VESICLES;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
34
Recensione:
Indirizzi per estratti:
Citazione:
A.J. Pacitti et al., "CHARACTERIZATION OF NA-INDEPENDENT GLUTAMINE TRANSPORT IN RAT-LIVER()", The American journal of physiology, 265(1), 1993, pp. 70000090-70000098

Abstract

In hepatic plasma membrane vesicles (HPMVs) from rat liver, we observed that approximately 40-45% of Na+=independent glutamine uptake occurs by a saturable carrier-mediated process. This component of glutamineuptake is mediated by a transport agency distinct from that of previously described systems for the Na+-independent transport of amino acids. Transport of glutamine was electroneutral and occurred into an osmotically active space with negligible membrane binding. The model system L substrate 2-amino-2-norbornane-carboxylic acid (BCH) showed no appreciable inhibition of Na+-independent glutamine uptake by HPMVs but effectively inhibited the uptake of leucine, a classic system L substrate, in identical vesicle preparations. Further evidence against systemL-mediated glutamine transport was provided by the pH dependence and the lack of trans-stimulation of saturable uptake. Competition experiments with selected amino acids revealed a pattern of inhibition of glutamine transport that was inconsistent with assignment of glutamine entry to systems asc, T, or systems for the Na+-independent transport ofthe charged amino acids. This BCH-noninhibitable transport system in HPMVs was highly selective for glutamine, histidine, and, to a lesser extent, asparagine. Inhibition of Na+-independent glutamine transport by leucine was noncompetitive in nature. On the basis of Na+ independence, pH sensitivity, absence of trans-stimulation, and an amino acid selectivity similar to that of the previously described hepatic Na+-dependent system N, we have provisionally designated the glutamine transport agency described in this article as system ''n.''

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 28/01/21 alle ore 07:42:09