Tag Archives: contractile activity
A new selective inhibitor of the Mg(2+), ATP-dependent sodium pump calix[4]aren С-1130 as a modulator of myometrial contraction energy
S. O. Kosterin1*, O. V. Tsymbalyuk2, R. V. Rodik3, V. I. Kalchenko3
1Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
*e-mail: kinet@biochem.kiev.ua;
2Taras Shevchenko National University of Kyiv, Ukraine;
e-mail: otsymbal@knu.ua;
3Institute of Organic Chemistry, National Academy of Sciences of Ukraine, Kyiv;
e-mail: manli@ioch.kiev.ua
Received: 19 November 2025; Revised: 23 January 2026;
Accepted: 03 April 2026; Available on-line: April 2026
It is known, that the functioning of non-electrogenic 2Na+-Ca2+-exchange system, localized in the myometrium cells plasma membrane, is ensured by the energy of the transmembrane sodium gradient, created by the Mg2+, ATP-dependent sodium pump. The aim of the study was to determine how the inhibitor of this pump calix[4]arene С-1130 affects the mechanokinetics and energy of myometrium contraction-relaxation. The experiments were conducted using female Wistar rats. The contractile activity of the longitudinal smooth muscles of the uterine horns was studied tensometrically. The method of determining the mechanical work А and power N at any time moment t of the of smooth muscle isotonic contraction-relaxation complete cycle was developed and tested in the tensometric experiments. Calix[4]arene С-1130 was dissolved in dimethylsulfoxide and introduced into the working solutions in a 10-5 М concentration. It was found that under calix[4]arene С-1130 treatment, the relative values of the mechanical work A were achieved at a time when the contraction-relaxation cycle under control conditions was practically completed, while the maximum values of power N were reached faster than in the control. These results indicate that calix[4]arene С-1130 was capable of inducing the increase in the maximal value of the smooth muscle mechanical work, promoting its relaxation without a considerable change in the contraction power. The developed methodology may be useful for the comparative study of the pharmacological drugs effect on the smooth muscles contractile activity in the “norm-pathology” format.
Indicators of musculus soleus contractility disorder in obese rats
D. M. Nozdrenko, O. V. Rizun, O. O. Kalmukova,
M. Yu. Kuznietsova, N. G. Raksha, T. I. Halenova*,
O. V. Lynchak, Yu. I. Prylutskyy
Taras Shevchenko National University of Kyiv, Ukraine;
*e-mail: galenovatanya@knu.ua
Received: 23 October 2025; Revised: 12 November 2025;
Accepted: 30 January 2026; Available on-line: 23 February 2026
Obesity has become a widespread issue across the globe, reaching epidemic proportions. Being overweight is a known risk factor for developing impairments in muscle performance. The aim of the study was to estimate mechanokinetic parameters of musculus soleus contraction in obese animals to better understand the possible impact of obesity on muscle contractile activity, tissue structure and appearance of damage markers in the blood. Experiments were carried out on 40 male white non-linear rats, divided equally into two groups. Control group were fed a standard diet for 10 weeks. Rats in the obesity group were maintained on a high-fat diet for the same time period. At the end of the experiment animals were anesthetized, musculus soleus was dissected, the ventral roots were severed from the spinal cord. Stimulation was performed by electrical impulses generated by a pulse generator. Tissue samples histological analysis was done with the use of Van Gieson’s trichrome and Sudan Black staining. Creatinine concentration, creatine phosphokinase (CPK) and lactate dehydrogenase (LDH) activity in the blood was determined. Reduction in musculus soleus maximum contraction force and muscle force impulse, prolonged relaxation time and delayed muscle return to initial state in obese animals as compared to control group were detected indicating on skeletal muscle fatigue. The appearance of intramyocellular lipid droplets and increased amount of intramuscular collagen fibers in the muscle tissue, as well as the elevated creatinine level and increased LDH and CPK activity in the blood, confirmed the impairment of muscle state in obese rat.