Т. О. Veklich¹*, R. V. Rodik², О. V. Tsymbalyuk³,
О. V. Shkrabak¹, O. V. Maliuk¹, S. O. Karakhim¹,
S. H. Vyshnevskyi³, V. І. Kalchenko³, S. O. Kosterin¹

¹Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
*e-mail: veklich@biochem.kiev.ua;
²Institute of Organic Chemistry, National Academy of Sciences of Ukraine, Kyiv;
³Educational and Scientific Institute of High Technologies,
Taras Shevchenko National University of Kyiv, Kyiv, Ukraine;

Received: 01 September 2023; Revised: 23 October 2023;
Accepted: 01 December 2023; Available on-line: 18 December 2023

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 (І_0.5 = 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.