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Neurochem Int. 2004 Oct;45(5):759-64.

Gliotoxin induces Mg2+ efflux from intact brain mitochondria.

Author information

1
Dipartimento di Chimica Biologica, Universita' di Padova and Istituto di Neuroscienze del C.N.R., Unita' per lo Studio delle Biomembrane, Via G. Colombo 3, 35121 Padua, Italy.

Abstract

Gliotoxin (GT) is a hydrophobic fungal metabolite of the epipolythiodioxopiperazine group which reacts with membrane thiols. When added to a suspension of energized brain mitochondria, it induces matrix swelling of low amplitude, collapse of membrane potential (DeltaPsi), and efflux of endogenous cations such as Ca2+ and Mg2+, typical events of mitochondrial permeability transition (MPT) induction. These effects are due to opening of the membrane transition pore. The addition of cyclosporin A (CsA) or ADP slightly reduces membrane potential collapse, matrix swelling and Ca2+ efflux; Mg2+ efflux is not affected at all. The presence of exogenous Mg2+ or spermine completely preserve mitochondria against DeltaPsi collapse, matrix swelling and Ca2+ release. Instead, Mg2+ efflux is only slightly affected by spermine. Our results demonstrate that, besides inducing MPT, gliotoxin activates a specific Mg2+ efflux system from brain mitochondria.

PMID:
15234120
DOI:
10.1016/j.neuint.2004.01.001
[Indexed for MEDLINE]

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