Modulators of TRPM7-magnesium channels alter the contractile activity of rat uterine smooth muscle

Author(s):  
Carolin Mestermann ◽  
Thomas Noack ◽  
Robert Patejdl
PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0252438
Author(s):  
Aleksandra Zygmuntowicz ◽  
Włodzimierz Markiewicz ◽  
Tomasz Grabowski ◽  
Artur Burmańczuk ◽  
Alla Vyniarska ◽  
...  

Quercetin is a polyphenolic flavonoid occurring in leaves, stems, flowers and fruits of many plants. In traditional Chinese medicine, it is used as a natural therapeutic agent with a broad spectrum of activities (antioxidant, neuroprotective, anti-inflammatory, anticancer, antibacterial and antiviral). Moreover, quercetin affects function of the reproductive tract, however the knowledge of this activity is still fragmentary. Therefore, this study aimed to determine the influence of quercetin on the contractile activity of the porcine myometrium collected from immature (n = 6), cyclic (n = 6) and early pregnant (n = 6) gilts. Strips of the myometrium (comprising longitudinal and circular layer) were resected from the middle part of the uterine horns and the isometric contractions were recorded. After 60–90 min of preincubation, the strips were stimulated with quercetin in increasing (10−13–10−1 M) concentrations and the changes in the tension amplitude and frequency of contractions were measured. Quercetin decreased (P<0.01–0.001) the amplitude of contractions at concentrations 10−11–10−1 M and 10−10–10−1 M in cyclic and early pregnant groups, respectively. The frequency of contractions decreased in all groups but was the highest (at concentrations 10−11–10−1 M; P<0.05–0.001) in the cyclic group and the lowest (at concentrations 10−5–10−1 M; P<0.01) in the immature group. The tension decreased only in the cyclic group after quercetin administration in high concentrations (10−6–10−1 M; P<0.05–0.01). The results indicate that quercetin causes relaxation of the porcine uterine smooth muscle but this activity is strongly related to the physiological status of the gilts.


1985 ◽  
Vol 249 (1) ◽  
pp. C20-C31 ◽  
Author(s):  
W. C. Cole ◽  
R. E. Garfield ◽  
J. S. Kirkaldy

We have tested the hypothesis that an increase in direct intercellular communication accompanies the development of gap junctions (GJs) between rat uterine smooth muscle cells at parturition. Intercellular communication in these tissues was studied by exposing one portion of small strips of myometrium to 2-[3H]deoxy-D-glucose (2-DG) and determining the longitudinal distribution of tracer after a 5-h period of diffusion. The distribution of 2-DG was greater in parturient compared with ante- and postpartum tissues. Similarly, the apparent diffusion coefficient of 2-DG was almost 10-fold greater in delivering tissues (1.86 X 10(-6) cm2/s) than before (0.199 X 10(-6) cm2/s) or after (0.296 X 10(-6) cm2/s) parturition. Control experiments indicated that the redistribution of 2-DG was dependent on the presence of GJs and was the result of intracellular and direct cell-to-cell diffusion. The appearance of GJs is the myometrium at term facilitates direct intercellular communication between uterine smooth muscle cells during labor. This improved communication may be responsible for synchronizing and coordinating electrical, metabolic, and contractile activity in the uterine wall and, hence, the effective expulsion of fetuses.


1993 ◽  
Vol 265 (4) ◽  
pp. C976-C985 ◽  
Author(s):  
K. Anwer ◽  
C. Oberti ◽  
G. J. Perez ◽  
N. Perez-Reyes ◽  
J. K. McDougall ◽  
...  

The role of Ca(2+)-activated potassium (KCa) channels in the regulation of membrane potential, intracellular free calcium ([Ca2+]i) and contraction was investigated in uterine smooth muscle and myometrial cells. In an immortalized human myometrial cell line, oxytocin increased [Ca2+]i and [3H]inositol phosphate formation. Relaxin attenuated the oxytocin-induced increase in [Ca2+]i. In cell-attached patches, membrane depolarization activated a large-conductance KCa channel (179 +/- 4 pS). Iberiotoxin (IbTX), a potent blocker of "maxi" KCa channels (A. Galvez, G. Gimenez-Gallego, J. P. Reuben, L. Roy-Contanciin, P. Feigenbaum, G. J. Kaczorowski, and M. L. Garcia. J. Biol. Chem. 265: 11083-11090, 1990) produced long closed events (approximately 6 min) in these channels. In agreement with this blockage, IbTX depolarized the cells by 9.8 +/- 2.8 mV and caused a dose-dependent increase in [Ca2+]i with a half-maximal effective concentration of 0.79 nM. IbTX also caused phasic contractions in human myometrial strips and increased both the frequency and force of spontaneous contractions in estrogen-primed rat myometrial strips. Moreover, myometrial contractility was also affected by 1 mM tetraethylammonium, a concentration that blocks uterine smooth muscle KCa channels when applied to the extracellular side (G. J. Perez, L. Toro, S. D. Erulkar, and E. Stefani. Am. J. Obstet. Gynecol. 168: 652-660, 1993). These results strongly suggest that the large conductance KCa channels may actively participate in the control of human myometrial cell membrane potential and [Ca2+].


1986 ◽  
Vol 251 (3) ◽  
pp. C411-C420 ◽  
Author(s):  
W. C. Cole ◽  
R. E. Garfield

We have investigated whether direct intercellular communication between uterine smooth muscle cells of delivering rats is influenced by intracellular adenosine 3',5'-cyclic monophosphate concentration ([cAMPi]) and agents relevant to the hormonal control of pregnancy and parturition. The rate of diffusion of phosphorylated 2-[3H]deoxy-D-glucose (2-DG) in strips of longitudinal myometrium from rats in labor, indicated by the apparent diffusion coefficient for this molecule, was observed to be significantly reduced in tissues with elevated [cAMPi] (after treatment with dibutyryl cAMP, 8-bromo cAMP, forskolin, and theophylline) in the absence of any change in the area of gap junctions (GJs). Similarly, several agonists that elevate [cAMPi] in this tissue (e.g., isoproterenol, relaxin, carbacyclin, prostaglandin E2) also reduced 2-DG diffusion. These data suggest that the permeability of GJs in uterine smooth muscle may be regulated by [cAMPi] and physiologically relevant agonists. Control of GJ permeability may be important for the physiological regulation of intercellular communication and the extent of synchronous contractile activity in the uterine wall during pregnancy and parturition.


Author(s):  
Olena M. Semenykhina ◽  
Olga V. Bazilyuk ◽  
Yulia P. Korkach ◽  
Vadim F. Sagach

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