| Autor: |
Masini, Alberto, Ceccarelli, Daniela, Trenti, Tommaso, Gallesi, Daniela, Muscatello, Umberto |
| Zdroj: |
Biochimica et biophysica acta. Bioenergetics; July 1992, Vol. 1101 Issue: 1 p84-89, 6p |
| Abstrakt: |
The effect of exogenous octadeccadienoic acid hydroperoxide (HPODE) on the functional properties of inner membrane of isolated rat liver mitochondria, as evaluated by the measurement of the membrane potential (Δψ) has been studied. Very low concentrations of HPODE (1.5–4.5 nmol/mg prot.) do not modify the Δψ of control mitochondria appreciably while bringing about the drop of Δψ, in a concentration-dependent mode, in mitochondria with a GSH level diminished by approx. 60%. Mitochondrial GSH depletion was obtained by intraperitoneal administration of buthionine sulfoximine, a specific inhibitor of GSH synthesis, to rats. The presence in the incubation system of GSH-methyl ester which normalizes mitochondrial GSH, fully prevents any drop in levels of Δψ induced by HPODE. The same protective effect has been presented by EGTA, which chelates the available Ca2+. Neither an antioxidant nor a specific inhibitor of mitochondrial phospholipase Ab2are able to prevent the HPODE effect. From the results obtained we can assume that HPODE itself, at the concentrations used here, induces permeability changes in the inner membrane, with the loss of coupled functions, when the GSH mitochondrial level is below a critical value. |
| Databáze: |
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