The contribution of endogenous polyamines to the permeability transition of rat liver mitochondria.
Spermine and spermidine are present in rat liver mitochondria at the concentrations of 3.5 and 1.8 nanomoles/mg protein, respectively. Addition of 50 microM Ca2+ and 1 mM Pi to respiring mitochondria induces, concomitantly with mitochondrial swelling and Mg2+ efflux, a consistent release of polyamines, which is either prevented by cyclosporin A or Mg2+. Addition of 0.1 mM spermine to mitochondria deenergized by Ca2+ and phosphate restores, like 1 mM Mg2+, transmembrane potential at the physiological level, while either cyclosporin A or ADP are ineffective. The presence of polyamines in the matrix space should be considered relevant, like Mg2+, in controlling the permeability transition of liver mitochondria.
Tassani
V
V
Dipartimento di Chimica Biologica, Università di Padova, Italy.
Campagnolo
M
M
Toninello
A
A
Siliprandi
D
D
D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D016572:Cyclosporine / Q000494:pharmacology; D007700:Kinetics; D008274:Magnesium / Q000378:metabolism; D008930:Mitochondria, Liver / Q000502:physiology*; D008933:Mitochondrial Swelling / Q000187:drug effects; D010539:Permeability; D010710:Phosphates / Q000494:pharmacology; D051381:Rats; D013095:Spermidine / Q000378:metabolism*; D013096:Spermine / Q000378:metabolism*
D010710:Phosphates; D013096:Spermine; D016572:Cyclosporine; D008274:Magnesium; D002118:Calcium; D013095:Spermidine