Release of cytochrome c from liver mitochondria during permeability transition

SP Kantrow, CA Piantadosi - Biochemical and biophysical research …, 1997 - Elsevier
SP Kantrow, CA Piantadosi
Biochemical and biophysical research communications, 1997Elsevier
The mitochondrial permeability transition (PT) follows opening of megachannels in the inner
membrane and may be part of a programmed death pathway. Recently a role for cytochrome
c in programmed cell death has been proposed, although its relationship to PT has not been
been determined. We studied the release of cytochrome c from liver mitochondria
undergoing PT. Well-coupled mitochondria treated with 5 mM atractyloside (ATR) or 100 μM
calcium chloride were found to undergo PT and release cytochrome c into the incubation …
The mitochondrial permeability transition (PT) follows opening of megachannels in the inner membrane and may be part of a programmed death pathway. Recently a role for cytochrome c in programmed cell death has been proposed, although its relationship to PT has not been been determined. We studied the release of cytochrome c from liver mitochondria undergoing PT. Well-coupled mitochondria treated with 5 mM atractyloside (ATR) or 100 μM calcium chloride were found to undergo PT and release cytochrome c into the incubation buffer within 5 minutes. Control mitochondria and mitochondria treated with the uncoupler FCCP did not undergo PT or release cytochrome c at 5 or 15 minutes. PT induced by ATR could be prevented by pretreatment with 10 μM cyclosporin A. Mitochondria incubated with ATR or calcium caused a 20-30% decrease in electron transfer rate via cytochrome c and cytochrome c oxidase. We conclude that cytochrome c release is an early event during mitochondrial PT, and is sufficient to decrease electron transfer through the terminal electron transport components of the mitochondrion.
Elsevier