title: [Ca2+/H(+)-exchange in myometrium mitochondria].
abstract: Using the fluorescent probe Fluo-4 AM the authors have identified Na(+)-independent Ca2+H(+)-exchange in isolated mitochondria of rat myometrium and studied its individual properties. Formation of directional protons gradient in the matrix of mitochondria causes antyporte release of Ca2+, which has been previously accumulated in energetic processes (in the presence of Mg-ATP and succinate). The functioning of Ca2+/H(+)-exchange depends on the proton gradient and is characterized by reversibility, in case of extramitochondria environment alkalization the additional accumulation of Ca2+ by organelles is recorded. Monovalent cations gradients (Na+, K+, Li+) do not cause the release of Ca2+ from mitochondria. Rate of Ca2+/H(+)-exchange is growing in terms of increasing deltapH on the mitochondria membrane and kinetics of deltapH-induced Ca2+ release from the matrix corresponds to the laws of first order reaction. Research of Ca2+/H(+)-exchange some properties in the myometrium mitochondria showed that the above transport process is of electrogenic nature, perhaps it is done in a 1: 1 stechiometry (Hill coefficient on H+ close to 1) and is able to adjust matrix Ca2+ concentration under physiological conditions (pH activation of about 6.9). Thus, in the inner membrane of the myometrium mitochondria the available system of the secondary active Ca(2+)-transport from the matrix of these organelles to myoplasm and the functioning of Ca2+/H(+)-exchanger may underlie this process.
authors.forename: O V
authors.initials: OV
authors.lastname: Kolomiiets'
authors.forename: Iu V
authors.initials: IuV
authors.lastname: Danylovych
authors.forename: H V
authors.initials: HV
authors.lastname: Danylovych
authors.forename: S O
authors.initials: SO
authors.lastname: Kosterin
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000814:Aniline Compounds; D000818:Animals; D017920:Antiporters / Q000378:metabolism*; D017301:Ca(2+) Mg(2+)-ATPase / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000378:metabolism*; D027682:Cation Transport Proteins / Q000378:metabolism*; D002413:Cations, Divalent; D002414:Cations, Monovalent; D005260:Female; D006863:Hydrogen-Ion Concentration; D017136:Ion Transport; D007700:Kinetics; D053078:Membrane Potential, Mitochondrial / Q000502:physiology; D008928:Mitochondria / Q000378:metabolism*; D051336:Mitochondrial Membranes / Q000378:metabolism*; D009215:Myometrium / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism; D051381:Rats; D012964:Sodium / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D019802:Succinic Acid / Q000378:metabolism; D014966:Xanthenes
chemical_list: D000814:Aniline Compounds; D017920:Antiporters; D015220:Calcium Channels; D027682:Cation Transport Proteins; D002413:Cations, Divalent; D002414:Cations, Monovalent; C409648:Fluo 4; D014966:Xanthenes; C027614:calcium-hydrogen antiporters; C034703:mitochondrial calcium uniporter; D000255:Adenosine Triphosphate; D012964:Sodium; D019802:Succinic Acid; D017301:Ca(2+) Mg(2+)-ATPase; D011188:Potassium; D002118:Calcium