ISSN:
1573-4919
Keywords:
Bcl-2
;
Ca2+
;
hepatoma
;
liver
;
mitochondrial permeability transition
;
tumor cells
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
Notes:
Abstract Zajdela hepatoma mitochondria were able to accumulate two to five times more Ca2+ than rat liver mitochondria before the permeability transition was induced. Pulses of Ca2+ were given in series to determine the Ca2+ threshold by recording changes in [Ca2+] and membrane potential, the permeability transition causing the release of accumulated Ca2+ and collapse of the membrane potential. Hepatoma mitochondria had lower Ca2+ efflux rates, higher net Ca2+ uptake rates and lower phosphorylation rates than liver mitochondria. Since the differences in regard to induction of the permeability transition might be due to higher expression of the Bcl-2 protein in hepatoma cells than in hepatocytes, the transcription of Bcl-2 and the proteins reacting with a Bcl-2 polyclonal antiserum were estimated by Northern and Western blotting, respectively. Hepatoma cells had two Bcl-2 specific mRNA bands of 7 and 2.4 kb, and substantial amounts of the Bcl-2 protein, whereas in liver cells and mitochondria these were not detected. Both cell lines had a reactive band at 19-20 kDa, and hepatocytes a small band at 31-32 kDa. Bcl-2 antibodies stimulated the permeability transition potently in hepatoma mitochondria.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1006913526643
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