Kinetics of relaxation of rat myometrium in conditions of inhibition of plasma memb­rane calcium pump and systems of active Ca2+ transport of intracellular Ca2+-depot

Tsymbalyuk, O. V.

doi:10.30970/sbi.1202.565

Cited by 4 publications

(2 citation statements)

References 23 publications

(28 reference statements)

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“…In the presence of С-1087, there were no changes in the kinetics of the force accumulation (isometric contraction and isotonic shortening): in all cases, the maximal velocities of the contraction phase (V c and V nc ) did not demonstrate statistically significant changes as compared with the control. It should be noted that similar kinetic effects were also observed against the background of calixarenes С-90 and С-716 [39,40].…”

Section: Electronic Shielding Of Methylene Protons By a Phenyl Ring I...supporting

confidence: 67%

Thiacalix[4]arene С-1087 is the selective inhibitor of the calcium pump of smooth muscle cells plasma membrane

Veklich,

Rodik,

Tsymbalyuk

et al. 2023

Ukr.Biochem.J.

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The enzymatic and kinetic analyses were used to demonstrate that 5,11,17,23-tetra(trifluoro)methyl(phenylsulfonylimino)methylamino-25,27-dihexyloxy-26,28-dihydroxythiacalix[4]arene С-1087 effectively inhibited the Са2+,Mg2+-АТРase activity of the rat myometrium cells plasma membrane (І0.5 = 9.4 ± 0.6 µM) with no effect on the relative activity of other membrane ATPases. With the use of confocal microscopy and Ca2+-sensitive fluorescent probe fluo-4, it was shown that the application of thiacalix[4]arene С-1087 to the immobilized uterus myocytes increased the cytosolic concentration of Ca2+. Tenzometric studies of rat uterus smooth muscles with the subsequent mechanokinetic analysis revealed that thiacalix[4]arene С-1087 considerably decreased the maximal velocity of the relaxation of both spontaneous contractile response and contraction induced by hyperpotassium solution. Keywords: contraction-relaxation mechanokinetics, cytosolic Ca(2+), myometrium, plasma membrane Са(2+)‚Mg(2+)-АТРase, smooth muscle cell, thiacalix[4]arene

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Section: Electronic Shielding Of Methylene Protons By a Phenyl Ring I...supporting

confidence: 67%

Thiacalix[4]arene С-1087 is the selective inhibitor of the calcium pump of smooth muscle cells plasma membrane

Veklich,

Rodik,

Tsymbalyuk

et al. 2023

Ukr.Biochem.J.

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“…Mechanokinetic effects of thiacalix[4]arene C-1087 in combination with blocking of NO-synthases activity. A convenient pharmacological model for the study of the processes of SM contraction via the activation of Са 2+ inflow via the potentialgoverned channels and further extrusion of these cations during the relaxation phase is HPS-induced contraction (Trujillo et al, 2000;Tsymbalyuk, 2018). It was shown in our previous studies (Veklich at al., 2023) that under the conditions of preliminary incubation of SM preparations of the rat uterine with thiacalix[4]arene С-1087 (10 µM) there was a considerable slowdown in the process of relaxing the HPS-induced contraction and the index of the normalized maximal velocity of the relaxation phase decreased more than twice compared to the control.…”

Section: Serca Activity Blockingmentioning

confidence: 95%

Thapsigargin-resistant thiacalix[4]arene C-1087-sensitive component of the contractile activity in rat myometrium reflects the functioning of plasma membrane calcium pump

Tsymbalyuk,

Veklich,

Rodik

et al. 2023

Biol. Stud.

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Background. According to existing knowledge, thiacalix[4]arene С-1087 is highly capable of inhibiting Са2+-pump (Са2+, Mg2+-АТРase) of the plasma membrane; at the same time it inhibits the functioning of Са2+-pump of the sarcoplasmic reticulum of uterine smooth muscles to some degree. The aim of this research was to study the effects of С-1087 on the concentration of Ca2+ ions and contractile activity of the rat myometrium cells using an inhibitor of Са2+-pump of the sarcoplasmic reticulum – thapsigargin. Materials and Methods. The experiments were conducted using outbred white non-pregnant rats. The contractile activity in the preparations of longitudinal SM of uterine horns with preserved endothelium was registered in the isometric mode. To determine the changes in [Ca2+]i level, myocytes were treated with probes Hoechst 33342 (to test the nucleus of the cell) and fluo-4 AM (to test the change in Са2+-concentration in the cell). Results. The tenzometric studies with the subsequent mechanokinetic analysis demonstrated that under the action of thapsigargin (0.5 µM), thiacalix[4]arene C-1087 (10 µM) caused considerable changes in the kinetics of the spontaneous contractile activity processes in the myometrium of rats, including the decrease in the maximal contraction velocity and the increase in the maximal relaxation velocity. By means of confocal microscopy with Ca2+-sensitive fluorescent probe fluo-4, it was demonstrated that the application of thiacalix[4]arene С-1087 to immobilized myocytes of the uterus against the background of thapsigargin caused a transient spike of Са2+-signal with the subsequent turn of the intracellular concentration of Ca ions to the stable increased level. The effects of С-1087 under the action of thapsigargin regarding the relaxation phase in the spontaneous myometrium contractions were removed after the preliminary blocking of nitric oxide synthases L-NAME (100 µM). Under the action of L-NAME, thiacalix[4]arene С-1087 (10 µM) caused complete inhibition of the relaxation process in the contraction of myometrium preparations, induced by high-potassium solution (80 mM). Conclusions. The primary reason for changes in the contractile activity and Ca2+-signal in uterine myocytes under the effect of thiacalix[4]arene С-1087 is its ability to inhibit Са2+-pump of the plasma membrane; further С-1087-induced changes in the smooth muscle tissues may be caused by the increased level of Са2+ concentration in myocytes. The obtained results demonstrate thiacalix[4]arene С-1087 is a promising compound for the elaboration of pharmacological preparations for modulating the contractile activity in smooth muscles, including myometrium.

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Involvement of KАТР-channels of plasma and mitochondrial membranes in maintaining the contractive function of myometrium of non-pregnant rat uterus

Tsymbalyuk

Vadzyuk

2020

Biol. Stud.

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Kinetics of relaxation of rat myometrium in conditions of inhibition of plasma membrane calcium pump and systems of active Ca2+ transport of intracellular Ca2+-depot

Cited by 4 publications

References 23 publications

Thiacalix[4]arene С-1087 is the selective inhibitor of the calcium pump of smooth muscle cells plasma membrane

Thiacalix[4]arene С-1087 is the selective inhibitor of the calcium pump of smooth muscle cells plasma membrane

Thapsigargin-resistant thiacalix[4]arene C-1087-sensitive component of the contractile activity in rat myometrium reflects the functioning of plasma membrane calcium pump

Involvement of KАТР-channels of plasma and mitochondrial membranes in maintaining the contractive function of myometrium of non-pregnant rat uterus

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Kinetics of relaxation of rat myometrium in conditions of inhibition of plasma memb­rane calcium pump and systems of active Ca2+ transport of intracellular Ca2+-depot

Cited by 4 publications

References 23 publications

Thiacalix[4]arene С-1087 is the selective inhibitor of the calcium pump of smooth muscle cells plasma membrane

Thiacalix[4]arene С-1087 is the selective inhibitor of the calcium pump of smooth muscle cells plasma membrane

Thapsigargin-resistant thiacalix[4]arene C-1087-sensitive component of the contractile activity in rat myometrium reflects the functioning of plasma membrane calcium pump

Involvement of KАТР-channels of plasma and mitochondrial membranes in maintaining the contractive function of myometrium of non-pregnant rat uterus

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Kinetics of relaxation of rat myometrium in conditions of inhibition of plasma membrane calcium pump and systems of active Ca2+ transport of intracellular Ca2+-depot