[H+-Ca2+-exchanger in the myometrium mitochondria: modulation of exogenous and endogenous compounds].

The properties of ΔpH-induced Ca2+-transport from isolated rat myometrium mitochondria was investigated. Ca2+-accu- mulation was carried out in the presence of Mg-ATP2- and succinate. Transport of Ca2+ recorded using Ca2+-sensitive fluorescent probe Fluo-4 AM.

[Ca2+/H(+)-exchange in myometrium mitochondria].

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.

[Nitric oxide as a possible regulator of energy-dependent Ca2+ transport in mitochondria of uterine smooth muscle].

The influence of the donor and the precursor of NO, namely 100 mM sodium nitroprusside and sodium nitrite on the energo-dependent Ca(2+)-transport in isolated mitochondria from rat myometrium was investigated. Changes in the mitochondrial matrix Ca(2+)-concentration was evaluated by spectrofluorimetry using Ca2+ sensitive probe Fluo-4 AM. Mg(2+)-ATP-dependent Ca(2+)-accumulation on mitochondria in the presence of succinate significantly stimulated by nitric oxide, in particular, 100 microM sodium nitroprusside amplified the transport by 1.

[Investigation of nitrosactive compounds influence on polarization of the mitochondrial inner membrane in the rat uterus myocytes using potential sensitive fluorescent probe DiOC6(3)].

The effect of nitrosactive compounds (sodium nitroprusside and sodium nitrite) on the polarization level of the uterus myocytes inner mitochondrial membrane using the confocal laser microscopy and fluorescent probe potentialsensitive DiOC6(3) (3,3'-dihexyloxacarbocyanine) was ivestigated. Colocalisation of mitochondrial membranes specific fluorescent probes (MitoTracker Orange CM-H2TMRos, 10 - nonyl acridine orange and DiOC6(3)) was demonstrated. It was shown that sodium nitroprusside at 0.

[Ca2+ accumulation study in isolated smooth muscle mitochondria using fluo-4 AM].

The opportunity of Ca2+-sensitive fluorescent dye Fluo-4 AM and spectrofluorimetry method application for the study of energy-dependent Ca2+ accumulation in mitochondria from uterus smooth muscle is proved. It has been found that the presence of mitochondrial preparation increases time-dependent fluorescent response considerably and this effect depends on Ca2+ concentration in the medium. Thus, in these conditions, deesterification active probe is formed which is sensitive to Ca2+.

[Investigation of the changes in uterine myocytes size depending on contractile activity modulators by photon correlation spectroscopy].

By using photon correlation spectroscopy the effect of contractile activity modulators of smooth muscle to the size (diameter) of rats uterine muscle cells was investigated. Cells were studied by using laser confocal microscopy as objects mostly oval or nearly oval form. The diameter of myocytes, assessed by photon correlation spectroscopy, was amounted 7-10 microm which is Consistent with the results obtained by using laser confocal microscopy.

[Changes in polarization of myometrial cells plasma and internal mitochondrial membranes under calixarenes action as inhibitors of plasma membrane Na+, K+-ATPase].

The influence of supramolecular macrocyclic compounds--calix[4]arenes C-97, C-99, C-107, which are ouabainomymetic high affinity inhibitors of Na+, K(+)-ATPase, on the polarization level of plasmic and mitochondrial membranes of rat uterine smooth muscle cells was investigated. The influence of these compounds on the myocytes characteristic size was studied. By using a confocal microscopy and specific for mitochondrial MitoTracker Orange CM-H2TMRos dye it was proved that the potential-sensitive fluorescent probe DiOC6(3) interacts with mitochondria.

[Registration of K(+)-equilibrium potential in myometrium cell plasma membrane and study of its modulation of NO(x) and H2O2, using flow cytometry method].

Prospects of the use of flow cytometry analysis for investigation of forming K(+)- equilibrium membrane potential on the experimental model of myometrium plasma membrane vesicles in the presence of valinomycine using potential-sensitive probe of DiOC6(3). Transmembrane potential magnitude corresponds to magnitude by Nernst's equation. H2O2 and NO2-, probably, increase permeability of membrane for K+ and result in potential dissipation.

[Hydrogen peroxide inhibits acetylcholinesterase of myometrium sarcolemma].

The action of hydrogen peroxide on acetylcholinesterase enzymatic activity in myometrium sarcolemma fraction is investigated. Hydrogen peroxide (0.1-26 microM), depending on the concentration, suppressed the activity.

[The action of nitrite-anions and hydrogen peroxide on surface properties of the smooth muscle plasmatic membrane].

In the presence of vesicular preparations of sarcolemma (near 70% reverse cytoplasmic sideways inward) fluorescence of ANS--1-(fenilamino)-8-naftylamine--rises more than 10 times. In the conditions of increase of concentration of sodium nitrite and hydrogen peroxide from 1 to 5 microM the probe fluorescence diminishes. Extinguishing of ANS fluorescence under the action of nitrite anions can be explained by chemical modification of the positively charged superficial groups (amino- and sulfhydrile).

[Effect of nitric oxides and hydrogen peroxide on Ca2+, Mg(2+)-ATPase and Mg(2+)-ATPase activity in myometrium sarcolemma].

The action of sodium nitroprusside, nitrite-anions and hydrogen peroxide on Ca2+, Mg(2+)-ATPase and Mg(2+)-ATPase (Ca(2+)-independent) enzymatic activity in myometrium sarcolemma fraction is investigated. It is established, that 0.1 mM sodium nitroprusside and 10(-8)-10(-5) M nitrite-anions essentially reduce Ca2+, Mg(2+)-ATPase activity whereas Mg(2+)-ATPase proved to be absolutely resistant to them.

[Characteristics of passive Ca2+ -transport from cells of the myometrium sarcoplasmic reticulum in rats].

With use of model ofpermeabilizated myocytes from rat uterus and 45Ca2+ it is shown, that passive Ca2+ transport from sarcoplasmic reticulum (cation has been preliminary accumulated in ATP-dependent process) is sensitive to 2 mM caffeine, 0,1 mM lidocaine, and also to exogenous Ca2+ (it was activated at increase in concentration Ca2+ from 10(-7) up to 10(-4) M and was suppressed at 10(-3)) and pH level (was stimulated by alkalization of medium), along with significant suppression of Mg2+ (0.2 - 4 mM). The analysis of the results received allows us to assume that the model used by us is adequate for studying processes of Ca2+ release from sarcoplasmic reticulum, mediated by ryanodine receptor channels.

[Effect of the active nitrogen and oxygen metabolities on the level of cGMP in uterus myocytes].

The level of cGMP in myocytes of uterus of rats at an action active metabolities of nitrogen and oxygen (NO, NO2- and H2O2) in the conditions of influence of progesteron on myocytes was studied. Cell suspension was selected with the use of collagenase and soy-bean inhibitor of tripsin. Determining the amount of cGMP was conducted with the use of standard kit produced by "Amersham" (Great Britain).

[Active nitrogen and oxygen metabolites change cAMP level in the uterus myocytes treated by progesterone].

The level of cAMP in the rats uterus myocytes under the effect of active metabolites of nitrogen and oxygen (NO, NO2- and H2O2) was studied in the conditions of progesterone influence on myocytes. Suspension of cells was selected with the use of collagenase and soy-bean inhibitor of tripsine. The amount of cAMP was determined with the use of standard reagents producted by "Amersham", England.

[Effect of oxygen and nitrogen active compounds on pH value in myometrium myocytes].

In suspension from a rat uterus using fluorescent pH1 probe BCECF-AM was established that the "apparent" pH1 value for this object was 6.72 +/- 0.02 at pHo = 7,4 (t = 25 degrees C, n = 5).

[Effect of steroid hormones and oxytocin on NO and H2O2 production in the endometrium].

The time and concentration regularities of influence of based estrogens (estrone), hystogenes (progesterone) and their analogs (ecdysterone and diethylstilbestrole) on production of NO and H2O2 by endometrium stroma cells. The level of NO2- in the cell suspension was determined on Grees reactive response, and H2O2 by permanganate measurements in paravariation with the use of horse-radisch peroxidase. It is supposed, that the studied steroids in the experiment conditions affect both the constitutive enzyme systems (membrane or nongenomic phase of activity), and the level of a gene expression (actynomycin D sensitive) and their activity is connected with the rising of concentration of cytosolic Ca2+ in cells.

[Possible role of ammonium as a paracrine regulator in the uterine tissue].

An opportunity of formation of ammonia (NH3) in utera endometrium and its influence on exchange of Ca2+ and H+ in plasmalemma of myometrium was investigated. Dissociation of endometrium stroma cells and myocytes suspension was carried from utera of pigs and rats in accordance with the traditional techniques. In suspension of stroma cells a rather high AMP-deaminase activity (53 +/- 2 mmol IMP/hour on 1 mg of protein) was determined.

[Enzymes and processes of activation of the endometrium stromal cells].

The endometrium stroma cells and properties of such key enzymes as acetylcholinesterase, Mg2+, Ca(2+)-ATPase, AMP-deaminase have been investigated in them. The activity of acetylcholinesterase in suspension of cells compounds is 9.8 +/- 0.

[Mechanisms of acetylcholine-dependent production of H2O2 and NO2- by stromal cells of endometrium].

The metabolism of NO(NO2-) and H2O2(O2-) by stroma cells of pig endometrium is NAD(P)H and glutathione-dependent process. The efficiency of biosynthesis and utilization of these metabolites appreciably depends on the state of SH-groups of the conforming ferment systems. And the reversible oxidation of SH-groups (maybe by the reaction products) results in the drop of biosynthesis rate.

[Effect of nitrite-anions on Ca2+ transport into the sarcolemma of myometrium].

The influence of nitrite-anions physiological concentration on Ca2+ input into vesicles was investigated when using the "outside-out" vesicles of myometrial plasmalemma and 45Ca2+. It was established that nitrite-anions increased Ca(2+)-permeability of plasmalemma and increased the affinity of cation-transport system. The effects are probably connected with reversible modification of glutamate residues that bound and transported Ca2+ within the membrane.

[Changes in hydrodynamic diameter of myometrium plasmalemma vesicles under artificial creation of transmembrane proton gradients].

A method of laser-correlation spectrophotometry was applied for finding the effect of proton transmembrane gradient on hydrodynamic diameter of plasmalemma smooth muscle vesicles. It is shown, that the building of protons gradient on the membrane of vesicles, pHi = 6.0; pHo = 7.

[Role of extra- and intracellular Ca2+ in changes of NO2- and H2O2 production by endometrium].

The work is aimed to find out the role of extra- and intracellular Ca2+ in cyclic mechanisms of NO2- and H2O2 metabolism in the stroma cells of endometrium activated by acetylcholine. High activity of Mg2+, Ca(2+)-ATP-ase is characteristic of stroma cells of the endometrium. This activity is tested in the presence of 0.

[Regulation of Ca(2+)-binding properties of calmodulin nitrite-anion and hydrogen peroxide].

The effect of NO2- and H2O2 on Ca(2+)-binding properties of calmodulin has been studied. The decrease of Ca2+ affinity for calmodulin and limiting quantity of the sites of cation cross-linking by the protein molecule under the effect of 1 nM NO2 and 10 nM H2O2. The increase of the acting substances concentration above physiological one results in the considerable decrease of the observed effects.

[Ca2+/H+-exchange mechanisms in myometrial plasmalemma cells].

Transport of 45Ca2+ into vesicules of hog myometrium plasmolemma under dissipation conditions of opposite-directed transmembrane gradient of protons (delta pH) was investigated. When studying some time regularities of the process, H+ dissipation was determined to have little effect on the initial velocity Vo (18 and 25 nmol Ca2+/1 mg of protein per 1 min at delta pH = 0 and delta pH = 1.5, respectively) and the time of semiaccumulation of cation (1.

[Ca2+ transport in the sarcolemma of the myometrium under its chemical modification].

The effect of some chemical modifying agents of the sarcolemma surface--dicyclohexicarbodiimide, trinitrobenzolsulphuric acid, dithiotreitol and nitrit-anions on passive transsarcolemmic accumulation of Ca2+ by the pig myometrium sarcolemma property oriented vesicules was studied. The comparative analysis of these substances action under proton transmembrane gradient dispersion is presented. The significance of surface amino-, carboxy groups and disulphide membrane bounds in Ca2+ transport mechanisms as a corresponding aspect to some contemporary ideas about Ca(2+)-channel has been defined.