Tag Archives: uterus
Biochemical and molecular-physiological aspects of the nitric oxide action in the utera
H. V. Danylovych, Yu. V. Danylovych
Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
e-mail: danylovych@biochem.kiev.ua
Received: 18 May 2021; Accepted: 12 November 2021
The sources of the nitric oxide (NO) formation in the uterus and the dynamics of changes in its content in different periods of organ functioning in human and animals are analyzed. The biochemical mechanisms of NO action on the myometrium contractile activity, the significance of NO in the physiological processes during pregnancy and labor, the importance of mitochondria as a reliable NO source in the smooth muscle and the possible ways of NO influence on Ca2+ transport and bioenergetic processes in mitochondria are considered. The authors’ data concerning ionic and membrane mechanisms of NO action on Ca2+-homeostasis of uterine myocytes, identification of nitric oxide in uterine smooth muscle mitochondria, biochemical characteristics of the NO-synthase reaction and the possible role of NO in the regulation of Ca2+ transport in these subcellular structures and in the electron transport chain functioning are presented and discussed.
Cаlіx[4]аrene С-956 is effective inhibitor of Н(+)-Сa(2+)-exchanger in smooth muscle mitochondria
G. V. Danylovych1, О. V. Kоlomiets1, Yu. V. Danylovych1, R. V. Rodik2, V. I. Kаlchenko2, S. О. Kоsterin1
1Palladin Institute of Biochemistry, National Academy of Science of Ukraine, Kyiv;
e-mail: danylovych@biochem.kiev.ua;
2Institute of Organic Chemistry, National Academy of Science of Ukraine, Kyiv
It was shown that calix[4]arene C-956 exhibited a pronounced concentration-dependent (10-100 μM) inhibitory effect on the H+-Ca2+-exchanger of the inner mitochondrial membrane of rat uterine myocytes (Ki 35.1 ± 7.9 μM). The inhibitory effect of calix[4]arene C-956 was accompanied by a decrease in the initial rate (V0) and an increase in the magnitude of the characteristic time (τ1/2) of the ΔрН-induced Са2+ release. At the same time, it did not affect the potential-dependent accumulation of Ca2+ in mitochondria. Thus, the action of calix[4]arene C-956 might be directed on increasing the concentration of Ca ions in the mitochondrial matrix. The calculation of basic kinetic parameters of the Ca2+ transport from isolated organelles (in the case of its non-zero stationary level), based on changes in fluorescence of Ca2+-sensitive dye Fluo-4 AM in mitochondria was performed. The proposed approach can be used for the kinetic analysis of the exponential decrease of the fluorescence response of any probes under the same experimental conditions.
Changes in polarization of myometrial cells plasma and internal mitochondrial membranes under calixarenes action as inhibitors of plasma membrane Na(+), K(+)-ATPase
G. V. Danylovych1, Yu. V. Danylovych1, O. V. Kolomiets1,
S. O. Kosterin1, R. V. Rodik2, S. O. Cherenok2, V. I. Kalchenko2,
A. Ju. Сhunikhin1, V. F. Gorchev1, S. A. Karakhim1
1Palladine Institute of Biochemistry, National Academy of Science of Ukraine, Kyiv
2Institute of Organic Chemistry, National Academy of Science of Ukraine, Kyiv
e-mail: danylovych@biochem.kiev.ua; vik@bpci.kiev.ua
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. Artificial potential collapse of plasmic membrane in this case was modeled by myocytes preincubation with ouabain (1 mM).
Further experiments performed using the method of flow cytometry with DiOC6(3) have shown that the compounds C-97, C-99 and C-107 at concentration 50-100 nM caused depolarization of the plasma membrane (at the level of 30% relative to control values) in conditions of artificial collapse of mitochondrial potential by myocytes preincubation in the presence of 5 mM of sodium azide.
Under artificial sarcolemma depolarization by ouabain, calixarenes C-97, C-99 and C-107 at 100 nM concentrations caused a transient increase of mitochondrial membrane potential, that is 40% of the control level and lasted about 5 minutes. Calixarenes C-99 and C-107 caused a significant increase in fluorescence of myocytes in these conditions, which was confirmed by confocal microscopy too.
It was proved by photon correlation spectroscopy method that the C-99 and C-107 caused an increase of characteristic size of myocytes.
Structural and functional bases of the intermolecular interaction of calix[4]arene C-97 with myosin subfragment-1 of myometrium
R. D. Labyntseva1, A. A. Bevza1, О. V. Bevza1,
S. O. Cherenok2, V. I. Kalchenko2, S. O. Kosterin1
1Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
e-mail: kinet@biochem.kiev.ua;
2Institute of Organic Chemistry, National Academy of Sciences of Ukraine, Kyiv;
e-mail: vik@bpci.kiev.ua
Calix[4]arene C-97 (code is shown) is the macrocyclic compound which has lipophilic intramolecular higly-structured cavity formed by four aromatic cycles, one of which on the upper rim is modified by methylene bisphosphonic group. It was shown that calix[4]arene C-97 (100 µM) efficiently inhibits ATPase activity of myosin subfragment-1 from pig myometrium, the inhibition coefficient І0.5 being 83 ± 7 µM. At the same time, this compound at 100 µM concentration significantly increases the effective hydrodynamic diameter of myosin subfragment-1, that may be indicative of intermolecular complexation between the calix[4]-arene and myosin head.
Computer simulation methods (docking, molecular dynamics, involving the Grid) have been used to clarify structural basis of the intermolecular interaction of calix[4]arene C-97 with myosin subfragment-1 of the myometrium; participation of hydrophobic, electrostatic and π-π (stacking) interactions between calix[4]arene C-97 and amino acid residues of myosin subfragment-1, some of them being located near the active site of the ATPase has been found out.