title: Influence of the energetic state of rat liver mitochondria on the sensitivity of the phosphate carrier towards SH reagents.
abstract: Phosphate transport into rat liver mitochondria was measured by the swelling technique in 0.1 M ammonium phosphate. Energized or non-energized mitochondria were preincubated with different thiol reagents and evidence is given that with a slow-reacting thiol reagent, ethacrynate, the inactivation of the phosphate carrier is obtained when mitochondria are energized, while poor or no inactivation occurs when mitochondria are non-energized or preincubated with Pi. Moreover, the inactivation depends on the presence of Mg2+ and on the nature of the substrate. Some comparative essays were done using N-ethylmaleimide as a thiol reagent, but no energy-linked variation of N-ethylmaleimide inhibition on phosphate transport was obtained. Taking into account the fact that both thiol-reagents incorporation into rat liver mitochondria is sitmulated by the presence of substrate, the different behaviour of these two thiol-reagents towards Pi transport is discussed on the basis of their different reactivity with SH groups.
mesh_terms: D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D004579:Electron Transport / Q000187:drug effects; D004734:Energy Metabolism; D004976:Ethacrynic Acid / Q000378:metabolism / Q000494:pharmacology*; D005033:Ethylmaleimide / Q000494:pharmacology*; D006885:Hydroxybutyrates / Q000378:metabolism; D008274:Magnesium / Q000494:pharmacology; D008930:Mitochondria, Liver / Q000378:metabolism*; D008933:Mitochondrial Swelling / Q000187:drug effects; D010710:Phosphates / Q000378:metabolism* / Q000494:pharmacology; D051381:Rats; D013386:Succinates / Q000378:metabolism; D014475:Uncoupling Agents / Q000494:pharmacology
chemical_list: D006885:Hydroxybutyrates; D010710:Phosphates; D013386:Succinates; D014475:Uncoupling Agents; D008274:Magnesium; D004976:Ethacrynic Acid; D005033:Ethylmaleimide