In squid axons intracellular Mg2+ is essential for ATP-dependent Na+ efflux in the absence and presence of strophanthidin.
Biochim Biophys Acta
; 728(3): 463-6, 1983 Mar 09.
Article
em En
| MEDLINE
| ID: mdl-6402014
ABSTRACT
The effect on Na+ efflux of removal of intracellular Mg2+ was studied in squid giant axons dialyzed without internal Ca2+. In the absence of Mg2i+, ATP was unable to stimulate any efflux of Na+ above the baseline of about 1 pmol . cm-2 . s-1. This behavior was observed in otherwise normal axons and in axons poisoned with 50 microM strophanthidin in the sea water. Reinstatement of 4 mM MgCl2 in excess to ATP in the dialysis solution brought about the usual response of Na+ efflux to ATP, external K+ and strophanthidin. The present experiments show that, regardless of the mechanism for the ATP-dependent Na+ efflux in strophanthidin-poisoned axons, this type of flux shares with the active Na+ extrusion the need for the simultaneous presence of intracellular ATP and Mg2+.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Sódio
/
Estrofantidina
/
Axônios
/
Trifosfato de Adenosina
/
Magnésio
Limite:
Animals
Idioma:
En
Revista:
Biochim Biophys Acta
Ano de publicação:
1983
Tipo de documento:
Article