Calix[4]arene C-90 selectively inhibits Ca2+,Mg2+-ATPase of myometrium cell plasma membrane.

The supramolecular compound calix[4]arene C-90 (5,11,17,23-tetra(trifluoro)methyl(phenylsulfonylimino)-methylamino-25,26,27,28-tetrapropoxycalix[4]arene) is shown to efficiently inhibit the ATP hydrolase activity of Ca2+,Mg2+-ATPase in the myometrium cell plasma membrane fraction and also in a preparation of the purified enzyme solubilized from this subcellular fraction. The inhibition coefficient I0.5 values were 20.

[Comparative study of calixarene effect on Mg2+ -dependent ATP-hydrolase enzymatic systems from smooth muscle cells of the uterus].

Investigation the influence of calyx[4]arenes C-90, C-91, C-97 and C-99 (codes are indicated) on the enzymatic activity of four functionally different Mg2+ -dependent ATPases from smooth muscle of the uterus: actomyosin ATPase, transporting Ca2+, Mg2+ -ATPase, ouabain-sensible Na+, K+ -ATPase and basal Mg2+ -ATPase. It was shown that calixarenes C-90 and C-91 in concentration 100 microM act multidirectionally on the functionally different Mg2+ -dependent ATP-hydrolase enzymatic systems. These compounds activate effectively the actomyosin ATPase (Ka = 52 +/- 11 microM [Ukrainian character: see text] 8 +/- 2 microM, accordingly), at the same time calixarene C-90 inhibited effectively activity of transporting Ca2+, Mg2+ -ATPase of plasmatic membranes (I(0,5) = 34.

[Effect of fluoroaluminate on the ATP-hydrolysing and Ca2+-transporting activity of the purified Ca2+, Mg2+-ATPase of myometrium cell plasma membranes].

Fluoroaluminate, known modulator of G-proteins, inhibits ATP-hydrolase activity of purified solubilized Ca2+, Mg(2+)-ATPase from myometrium cell plasma membranes and Ca(2+)-transporting activity of this enzyme reconstituted into azolectin liposomes: 10 mM NaF plus 10 microM AlCl3 inhibited the primary activity by 95% and--by 81%. Inhibition of purified both solubilized and reconstituted Ca2+, Mg(2+)-ATPases by fluoroaluminate evidences for the possibility of direct interaction AlF4- with this enzyme without involvement of G-protein. The sensitivity to fluoroaluminate of sarcolemmal Ca2+, Mg(2+)-ATPase from myometrium is similar to that of Ca2+, Mg(2+)-ATPase from stomach smooth muscle.

[Effect of spermine on activity of purified Ca2+, Mg2+-ATPase from plasma membranes of myometrium cells].

Effect of endogenous polyamine spermine, a relaxant of smooth muscle, on the activity of myometrium cell plasma membrane Ca2+, Mg(2+)-ATPase was studied. It was observed a tendency to activation of enzyme at the spermine concentrations 0.1-0.

[Utilization of purified myometrium cell plasma membrane Ca2+, Mg2+-ATPase for comparative estimation of the efficiency of energy-dependent Ca2+-transport inhibitors].

With the aim of comparative estimation of efficacy of well-known inhibitors of energy-dependent Ca(2+)-transporting systems their effects were investigated on the activity of purified Ca2+, Mg(2+)-ATPase of the myometrium cell plasma membranes. From the approved inhibitors (eosin Y, o-vanadate, thapsigargin, cyclopiazonic acid, ruthenium red, sodium azide) only eosin Y and o-vanadate are potent inhibitors of myometrium sarcolemma Ca(2+)-pump: the values of Ki equal 0.8 and 4.

[Effect of eosin Y on Ca2+, Mg2+-ATPase of the smooth muscle sarcolemma].

Eosin Y was studied with the aim to elucidate the mechanism of its inhibitory effect on the activity of Ca(2+)-transporting ATPase of myometrium cell plasma membrane. The inhibitor was studied for its effect on the maximal rate of the ATP-hydrolase reaction catalyzed by Ca2+, Mg(2+)-ATPase, on the enzyme affinity for the substrate and a possibility of enzyme activity protection under the inhibitor effect by the main reagents of ATP-hydrolase reaction. It was established that eosin Y decreased the turnover rate of this enzyme and his affinity for ATP.

[Some aspects of morphological manifestations of chronic gastritis in miners].

Morphology was studied together with the condition of the local cell-bound immunity in 24 patients who were not exposed to occupational hazards in their occupations and in 32 miners with a long length of service. The above subjects underwent esophagogastroduodenoscopy involving taking of gastrobiopsy specimens. In miners there prevailed chronic atrophic gastritis.

[Effect of calmodulin on myometrial cell membrane Ca2+,Mg2+-ATPase activity].

Myometrium cell plasma membrane Ca2+, Mg(2+)-ATPase purified by an affinity chromatography on calmodulin-sepharose 4B is calmodulin-dependent enzyme. Concentration of calmodulin required for half-maximal activation of enzyme was about 26 nM. By unlike to the enzymes originated from other tissues sensitivity to the calmodulin of the myometrial sarcolemma Ca(2+)-transporting ATPase was lower: calmodulin increased Vmax of ATPase about 1.

[Ca2+-transporting properties of myometrial plasma cell membrane Ca2+, Mg2+-ATPase reconstituted in liposomes].

Purified myometrium cells plasma membrane Ca2+, Mg(2+)-ATPase was reconstitute in liposomes in functionally active state by the method of cholate dialysis: it showed ATP-hydrolase activity increased by 0.8 microM A23187 average 4 times and it showed Mg2+, ATP-dependent Ca(2+)-transporting activity. Reconstituted system transported Ca2+ at an initial rate of 114.

[Effect of ethanol on the activity of the energy-dependent Ca2+-transporting system of myometrial cells].

In order of estimating some regularities of ethanol direct (effectory) effect to transmembrane calcium metabolism in the myometrium the action of this substance on the energy-dependent Ca(2+)-transporting systems of the uterine myocytes subcellular structures has been studied. The systems of Mg2+, ATP-dependent Ca2+ transport regarding their sensitivity to ethanol inhibitory effect were displayed as satisfying the following sequences: endoplasmic reticulum calcium pump > plasma membrane solubilized Ca2+, Mg2+, ATP-ase > mitochondrial Ca(2+)-accumulating system = plasma membrane calcium pump. Alongside with the latter, the oxytocin-insensitive component of Mg2+, ATP-dependent Ca2+ accumulation in the endoplasmic reticulum was defined to be less resistant to inhibitory effect of ethanol if compared with the oxytocin-sensitive one.

[Effect of organic solvents on catalytic and functional activity of transport Ca2+,Mg2+-ATPase from smooth muscle cell membrane].

It was shown that organic solvents (dioxane, acetone, ethanol, dimethylsulfoxide) at concentrations of < 10% suppress the activity of transport Ca2+, Mg(2+)-ATPase solubilized from plasmatic membranes of smooth muscle cells and Mg(2+)-ATP-dependent accumulation of Ca2+ ions in inverted membrane vesicles. It was found that one of the reasons for the inhibition of enzymatic and transport activity of Ca2+, Mg(2+)-ATPase by the action of these solvents is an increase in the attractive force between oppositely charged active center of the enzyme and the product (products) of the ATP-hydrolase reaction, which is induced by a decrease in the dielectric permeability of incubation medium.

Effects of eosin Y on the catalytic and functional activities of Mg2+,ATP-dependent calcium pump of smooth muscle cell plasma membrane.

Experiments with highly purified preparations of Ca2+,Mg2+-ATPase solubilized from sarcolemma and a fraction of inside-out sarcolemmal vesicles were performed to study the kinetics of inhibitory effects of eosin Y (0-100 microM) on the catalytic and transport activity of Mg2+,ATP-dependent calcium pump of myometrial cell plasma membrane. For both the Ca2+,Mg2+-dependent ATP hydrolysis and the Mg2+, ATP-dependent accumulation of Ca2+ the apparent inhibitory constant Ki was 0.8 microM.

[Effect of N-palmitoylethanolamine on energy-dependent transport of Ca2+ in vesicles of myometrium sarcolemma and their phospholipid composition].

N-palmitoylethanolamine (NPE) was studied for their effect on calcium pump of pig myometrium sarcolemma. NPE in concentration of 10 microM, stimulated by 28-46% Mg2+, ATP-dependent accumulation of Ca2+ in vesicles of plasmatic membrane of uterus myocytes taking absolutely no effect on passive release of this cation from them. NPE modified phospholipid composition of sarcolemma, causing the increase of percentage content of phosphatidylinositol (by 20.

[Effect of incubation medium dielectric permeability on enzymatic activity of functionally different ATPases of smooth muscles].

Some organic solvents (2-10%) have been comparatively studied for their effect on purified transporting Ca2+, Mg(2+)-ATPase, solubilized from the plasma membrane of smooth muscle cells and on actomyosine ATPase of the smooth muscle. The inhibiting effect of solvents on the initial maximum specific activity of Ca2+, Mg(2+)-ATPase corresponds to the sequence dioxane > acetone > ethanol > dimethyl sulfoxide (DMSO). Like the case with Ca2+, Mg(2+)-ATPase, dioxane inhibits actomyosine ATPase; acetone, ethanol and DMSO stimulate ATP-hydrolase reaction which is catalyzed by the complex of contractile proteins.

[Effect of inhibitors of energy-dependent Ca2+-transporting systems on calcium pumps of a smooth muscle cell].

Comparative investigation of sensitivity of calcium pumps of sarcolemma, endoplasmic reticulum and mitochondria of the smooth muscle to some inhibitors of energy-dependent Ca(2+)-transporting systems has been carried out in experiments made using the isotope method (45Ca2+) on the fraction of plasmatic membranes and suspension of chemically scanned cells of myometrium as well as on the preparation of highly purified Ca2+, Mg(2+)-ATPase which was solubilized from plasmatic membrane of uterus myocytes. It is proved that the calcium pump of mitochondria is selectively inhibited by ruthenium red (imaginary inhibition constant K, is equal to 0.6 microM); it is nonselectively inhibited by o-vanadate (Ki = 0.

[The diagnosis of chronic dust-induced bronchitis].

In dust-induced bronchitis, alterations in the pulmonary parenchyma present themselves in the main cellular indices for bronchioalveolar lavage (BAL), thought to be of much importance to its diagnosis. A total of 53 patients with initial and manifest forms of dust bronchitis underwent BAL. There has been found the following: a decrease in the mononuclear phagocyte system cells (MPhS) reflecting the state of local cellular immunity; rise in the amounts of coniophages, suggesting phagocytic activity of alveolar macrophages (AM) and dust blockade of MPhS cells; emergence and augmentation of counts of gigantic Pirogov-Langhans' cells characteristic of tuberculous granulomas, and also decrease in the counts of lymphocytes.

[Effect of dielectric permeability of culture media on the kinetics of the ATP hydrolysis reaction, catalyzed by Ca2+-transporting ATPase, solubilized from smooth muscle cell membrane].

Transport Ca2+,Mg(2+)-ATPase was solubilized from myometrial plasma membrane and purified by calmodulin-sepharose 4B affinity chromatography; the effect of dielectric permeability of incubation medium on kinetics of ATP hydrolysis by this enzyme was studied. Various concentrations of dimethylsulfoxide, ethanol, acetone, and dioxane (up to 10%) caused various dose-dependent inhibition of enzymatic ATP hydrolysis. The correlation between specific activity (A) of Ca2+,Mg(2+)-ATPase and dielectric permeability of the incubation medium (D) did not depend on the nature of organic solvents and was satisfactory approximated by similar lines in the Laidler-Scatchard coordinate system, i.

[Energy characteristics of an ATP-hydrolase reaction catalyzed by solubilized Ca2+,Mg2+-ATPase from smooth muscle cell membrane].

The effects of temperature, dielectric permeability and ionic strength on the activity of purified Ca2+, Mg(2+)-ATPase solubilized from myometrial sarcolemma have been studied under saturation of the enzyme with Ca2+, Mg2+ and ATP. The values of activation energy calculated from Arrhenius plots for both ATP hydrolase reactions catalysed by solubilized and reconstituted into azolectin liposomes Ca2+, Mg(2+)-ATPase and Mg2+, ATP-dependent Ca2+ transport by the reconstituted enzyme were 56.4 +/- 1.

[Uterotonic action of sigetin and its effect on the Mg2+, ATP-dependent transport and stationary metabolism of Ca2+ through the myometrial sarcolemma].

The effect of sigetin (dipotassium salt, meso-3, 4-di-(n-sulfophenyl)- hexane) on the electrical and mechanical activity, Ca2+, Mg2+-ATPase activity and Mg2+, ATP-dependent Ca2+ transport in uterine smooth muscle have been investigated. Sigetin caused depolarization of the cell membrane, leading to Ca2+ dependent spike discharge and development of mechanical response. Sigetin also produced deceleration of the relaxation of carbachol contracture controlled mostly by the sarcolemmal ATP driven Ca2+ pump.

[The role of cytological studies in the clinical management of dust-induced occupational diseases].

Mineral dusts induced immunopathies in silicosis patients can be traced through changes in the composition, quantity and activity of the mononuclear phagocytic system detected in broncho-pulmonary secretions. It was established that the development of chronic non-specific pulmonary diseases and dust bronchites were caused by local immunopathies. A cytologic test for pulmonary and bronchial local protection was proposed through determining the degrees of pathologic developments, gravity of bronchitis, its predominant syndromes, and surveillance of the therapeutic course.

[Catalytic properties of purified Ca2+,Mg2+-ATPase from the myometrium sarcolemma].

The catalytic properties of myometrium sarcolemmal Ca2+, Mg2(+)-ATPase purified from plasma membrane solubilizate by affinity chromatography on calmodulin-Sepharose were investigated. The enzyme isolated in the presence of azolectin revealed a calmodulin-independent affinity for Ca2+ (Km = 0.17 microM).

[Reconstruction of purified Ca2+,Mg2+-ATPase from the myometrium sarcolemma into liposomes and its catalytic properties].

The Ca2+, Mg2(+)-ATPase of the myometrium sarcolemma purified by the method of affinity chromatography on calmodulin sepharose is reconstituted into azolectin liposomes in the functionally active form by means of cholate dialysis. The ATPase-dependent accumulation of 45Ca is shown on the obtained model system. It makes up 95% of the total accumulation and may decrease to 43% under the effect of 0.

[Isolation and purification of Ca2+,Mg2+-ATPase from plasma membranes of the myometrium].

The preparation of the purified Ca2+, Mg2(+)-ATPase has been isolated from triton X-100 solubilizate of plasma membranes of the pig myometrium using the method of affinity chromatography on calmodulin-Sepharose 4B. The specific activity of the enzyme shows its 52-fold purification. The enzymic preparation practically has no Mg2(+)-ATPase activity.