Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
L-arginine effects on Na+ transport in M-1 mouse cortical collecting duct cells - A cationic amino acid absorbing epithelium
Autore:
Howard, DPJ; Cuffe, JE; Boyd, CAR; Korbmacher, C;
Indirizzi:
Univ Oxford, Physiol Lab, Oxford OX1 3PT, England Univ Oxford Oxford England OX1 3PT Physiol Lab, Oxford OX1 3PT, England Univ Oxford, Dept Human Anat & Genet, Oxford OX1 3QX, England Univ OxfordOxford England OX1 3QX Anat & Genet, Oxford OX1 3QX, England
Titolo Testata:
JOURNAL OF MEMBRANE BIOLOGY
fascicolo: 2, volume: 180, anno: 2001,
pagine: 111 - 121
SICI:
0022-2631(20010315)180:2<111:LEONTI>2.0.ZU;2-3
Fonte:
ISI
Lingua:
ENG
Soggetto:
NITRIC-OXIDE; SODIUM-CHANNELS; PH; SECRETION; AMILORIDE; REABSORPTION; MECHANISMS; SINGLE;
Keywords:
renal collecting duct; amiloride; epithelial sodium channel (ENaC); nitric oxide (NO); pH; cationic amino acid transport; system y(+); system y(+)L;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
37
Recensione:
Indirizzi per estratti:
Indirizzo: Korbmacher, C Univ Oxford, Physiol Lab, Parks Rd, Oxford OX1 3PT, England Univ Oxford Parks Rd Oxford England OX1 3PT X1 3PT, England
Citazione:
D.P.J. Howard et al., "L-arginine effects on Na+ transport in M-1 mouse cortical collecting duct cells - A cationic amino acid absorbing epithelium", J MEMBR BIO, 180(2), 2001, pp. 111-121

Abstract

The effect of L-arginine on transepithelial ion transport was examined in cultured M-l mouse renal cortical collecting duct (CCD) cells using continuous short circuit current (I-SC) measurements in HCO3-/CO2 buffered solution. Steady state I-SC averaged 73.8 +/- 3.2 muA/cm(2) (n = 126) and was reduced by 94 +/- 0.6% (n = 16) by the apical addition of 100 muM amiloride. This confirms that the predominant electrogenic ion transport in M-l cells isNa+ absorption via the epithelial sodium channel (ENaC). Experiments usingthe cationic amino acid L-lysine (radiolabeled) as a stable arginine analogue show that the combined activity of an apical system y(+) and a basal amino acid transport system y(+)L are responsible for most cationic amino acid transport across M-l cells, Together they generate net absorptive cationic amino acid flux. Application of L-arginine (10 mM) either apically or basolaterally induced a transient peak increase in Is, averaging 36.6 +/- 5.4 muA/cm(2) (n = 19) and 32.0 +/- 7.2 muA/cm(2) (n = 8), respectively. The response was preserved in the absence of bath Cl- (n = 4), but was abolished either in the absence of apical Naf (n = 4) or by epical addition of 100 muM amiloride (n = 6). L-lysine, which cannot serve as a precursor of NO, caused a response similar to that of L-arginine (Iz = 4); neither L-NMMA (100 muM; n = 3) nor L-NAME (1 mM; n = 4) (both NO-synthase inhibitors) affectedthe Is, response to L-arginine, The effects of arginine or lysine were replicated by alkalinization that mimicked the transient alkalinization of thebath solution upon addition of these amino acids. We conclude that in M-1 cells L-arginine stimulates Na+ absorption via a pH-dependent, but NO-independent mechanism. The observed net cationic amino acid absorption will counteract passive cationic amino acid leak into the CCD in the presence of electrogenic Na+ transport, consistent with reports of stimulated expression of Na+ and cationic amino acid transporters by aldosterone.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 28/01/21 alle ore 07:23:49