%0 Journal Article %T Cytoplasmic cellular structures control permeability of outer mitochondrial membrane for ADP and oxidative phosphorylation in rat liver cells. %+ Bioénergétique fondamentale et appliquée %+ Laboratoire de pathologie cellulaire %+ Institut de biochimie et génétique cellulaires (IBGC) %A Fontaine, Eric, M. %A Keriel, Christiane, M. %A Lantuéjoul, Sylvie %A Rigoulet, Michel %A Leverve, Xavier, M %A Saks, Valdur, A %< avec comité de lecture %@ 0006-291X %J Biochemical and Biophysical Research Communications %I Elsevier %V 213 %N 1 %P 138-46 %8 1995-08-04 %D 1995 %R 10.1006/bbrc.1995.2108 %M 7639727 %Z Life Sciences [q-bio]/Biochemistry, Molecular BiologyJournal articles %X The kinetics of regulation mitochondrial respiration by external ADP in permeabilized hepatocytes was studied further. In digitonin-permeabilized hepatocytes, the apparent Km for ADP in regulation of respiration was decreased from 275 +/- 35 microM in control to 48 +/- 8 microM by a treatment with trypsin (15 min, 0.125 mg/ml). In liver tissue homogenates, trypsin treatment similarly decreased the Km value for ADP. These results show that ADP diffusion in hepatocytes may be retarded due to some unknown cytoplasmic trypsin-sensitive protein factor(s) which may be lost during isolation of mitochondria. Since we have previously reported a limited permeability of the outer mitochondrial membrane in isolated hepatocytes (Saks et al. 1995, Biochem. Biophys. Res. Commun., 208, 919-926), we conclude that an important site of control of respiration in liver cells in vivo is located at the porin channels of the outer mitochondrial membrane. %G English %L inserm-00390247 %U https://inserm.hal.science/inserm-00390247 %~ INSERM %~ UGA %~ CNRS %~ UNIV-GRENOBLE1 %~ UMR5095