The effect of methylglyoxal-bis(guanylhydrazone) on mitochondrial Ca(2+) fluxes.
Methylglyoxal-bis(guanylhydrazone) (MGBG) induces a dose-dependent inhibition of the electrophoretic Ca(2+) uptake by rat liver mitochondria (RLM) without affecting the electrical membrane potential. MGBG is also able to inhibit the electroneutral Ca(2+) release from mitochondria. These effects result in a progressive increase of Ca(2+) level in suspending medium indicating that Ca(2+) uptake is inhibited at higher extent than Ca(2+) efflux. Spermine instead, induces a lowering of external Ca(2+) concentration. This action is reversed by MGBG which again raises the external Ca(2+) concentration then in the absence of spermine, though at a lower extent. The mechanism of MGBG effects and their implications on energy metabolism are discussed.
Salvi
Mauro
M
Dipartimento di Chimica Biologica, Universita' di Padova, Centro di Studio delle Biomembrane del CNR, Viale G. Colombo 3, I-35121, Padova, Italy.
Toninello
Antonio
A
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D008564:Membrane Potentials; D008930:Mitochondria, Liver / Q000187:drug effects* / Q000502:physiology; D008935:Mitoguazone / Q000494:pharmacology*; D051381:Rats
D004791:Enzyme Inhibitors; D008935:Mitoguazone; D002118:Calcium