Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
Ammonium interaction with the epithelial sodium channel
Autore:
Nakhoul, NL; Hering-Smith, KS; Abdulnour-Nakhoul, SM; Hamm, LL;
Indirizzi:
Tulane Univ, Sch Med, Dept Med, Nephrol Sect, New Orleans, LA 70112 USA Tulane Univ New Orleans LA USA 70112 hrol Sect, New Orleans, LA 70112 USA Tulane Univ, Sch Med, Dept Physiol, New Orleans, LA 70112 USA Tulane UnivNew Orleans LA USA 70112 t Physiol, New Orleans, LA 70112 USA Vet Affairs Med Ctr, New Orleans, LA 70112 USA Vet Affairs Med Ctr New Orleans LA USA 70112 r, New Orleans, LA 70112 USA
Titolo Testata:
AMERICAN JOURNAL OF PHYSIOLOGY-RENAL PHYSIOLOGY
fascicolo: 3, volume: 281, anno: 2001,
pagine: F493 - F502
SICI:
0363-6127(200109)281:3<F493:AIWTES>2.0.ZU;2-V
Fonte:
ISI
Lingua:
ENG
Soggetto:
CORTICAL COLLECTING TUBULE; XENOPUS-LAEVIS OOCYTE; NA+ CHANNELS; INTRACELLULAR PH; FUNCTIONAL EXPRESSION; GAMMA-SUBUNIT; TOAD BLADDER; TRANSPORT; RAT; PERMEABILITY;
Keywords:
mouse epithelial sodium channel; intracellular pH; ammonium ion permeability;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
42
Recensione:
Indirizzi per estratti:
Indirizzo: Nakhoul, NL Tulane Univ, Sch Med, Dept Med, Nephrol Sect, SL-45,1430 Tulane Ave, New Orleans, LA 70112 USA Tulane Univ SL-45,1430 Tulane Ave New Orleans LA USA 70112 USA
Citazione:
N.L. Nakhoul et al., "Ammonium interaction with the epithelial sodium channel", AM J P-REN, 281(3), 2001, pp. F493-F502

Abstract

The purpose of this study was to investigate the direct effect of NH3/NH4on mouse epithelial Na+ channels (mENaC) expressed in Xenopus oocytes. Two-electrode voltage-clamp and ion-selective microelectrodes were used to measure the Na+ current, intracellular pH (pH(i)), and ion activities in oocytes expressing mENaC. In oocytes expressing mENaC, removal of external Na+ reversibly hyperpolarized membrane potential by 129 +/- 5.3 mV in the absence of 20 mM NH4Cl but only by 100 +/- 7.8 mV in its presence. Amiloride completely inhibited the changes in membrane potential. In oocytes expressing mENaC, butyrate (20 mM) caused a decrease in pH(i) (0.43 +/- 0.07) similar to the NH4Cl-induced pH(i) decrease (0.47 +/- 0.12). Removal of Na+ in the presence of butyrate caused hyperpolarization that was not significantly different from that in the absence of butyrate at high pH(i) (in the absence of NH4Cl). Removal of external Na+ resulted in an outward current of 3.7 +/-0.8 muA (at -60 mV) The magnitude of this change in current was only 2.7 +/- 0.7 muA when Na+ was removed in the presence of NH4Cl, In oocytes expressing mENaC, NH4Cl also caused a decrease in whole cell conductance at negative potential and an outward current at positive potential. In the presenceof amiloride, steady-state current and the change in current caused by removal of Na+ were not different from zero. These results indicate that NH4Clinhibits Na+ transport when mENaC is expressed in oocytes. The inhibition of voltage changes is not due to intracellular acidification caused by NH4Cl. Permeability and selectivity of ENaC to NH4+ may play a role.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 19/09/20 alle ore 09:14:43