[Therapeutic doses of menadione reduce the rotenone-induced inhibition of respiration and membrane potential generation in mitochondria].
Menadione restores the rotenone-inhibited respiration of diaphragm muscle pieces in approximately the same degree as the respiration of heart mitochondria, i.e., to 30-40%. The respiration of heart mitochondria induced by 2-5 microM menadione (after its inhibition by rotenone) is partly coupled with ATP synthesis whose rate is much lower than that of oxidation of NAD-dependent substrates. The effects of menadione and mitochondrial energetics inhibitors on lymphocyte respiration and rhodamine 123 fluorescence in individual lymphocytes and their suspensions were compared. Menadione (2--5 microM) increased the rotenone + oligomycin suppressed delta psi m in lymphocytes. At 5-40 microM menadione did not act as an uncoupler and had little effect on the uncoupled lymphocyte respiration. All these effects were observed at menadione concentrations close to therapeutic ones. Vicasol, a water-soluble analog of menadione, exerted a similar effect.
Dedukhova
V I
VI
Mokhova
E N
EN
D000255:Adenosine Triphosphate / Q000096:biosynthesis; D000818:Animals; D066298:In Vitro Techniques; D007700:Kinetics; D008214:Lymphocytes / Q000378:metabolism; D008564:Membrane Potentials / Q000187:drug effects; D008929:Mitochondria, Heart / Q000378:metabolism* / Q000502:physiology; D009840:Oligomycins / Q000037:antagonists & inhibitors; D010084:Oxidation-Reduction; D010101:Oxygen Consumption / Q000187:drug effects*; D011817:Rabbits; D012132:Respiratory Muscles / Q000378:metabolism; D012402:Rotenone / Q000037:antagonists & inhibitors*; D014475:Uncoupling Agents; D014812:Vitamin K / Q000494:pharmacology*
D009840:Oligomycins; D014475:Uncoupling Agents; D012402:Rotenone; D014812:Vitamin K; D000255:Adenosine Triphosphate
Terapevticheskie dozy menadiona oslabliaiut tormozhenie dykhaniia i generatsii membrannogo potentsiala v mitokhondriiakh rotenonom.