Russian Journal of PhysiologyRussian Journal of PhysiologyРоссийский физиологический журнал им. И.М. Сеченова0869-81392658-655XThe Russian Academy of Sciences67931110.31857/S0869813925020082UINBFYEXPERIMENTAL ARTICLESЭКСПЕРИМЕНТАЛЬНЫЕ СТАТЬИResearch ArticleElectrical Activity of the Uterus in Rats at Different Stages of the Estrous CycleЭлектрическая активность матки крыс в разные фазы эстрального циклаRutkevichS. A.РуткевичС. А.
Belarus
rutkevitch@inbox.ruPihulP. G.ПигульП. Г.
Belarus
rutkevitch@inbox.ruPanimatskaYu. D.ПониматькоЮ. Д.
Belarus
rutkevitch@inbox.ruKazakevichV. B.КазакевичВ. Б.
Belarus
rutkevitch@inbox.ruVeresI. A.ВересИ. А.
Belarus
rutkevitch@inbox.ruSidorovA. V.СидоровА. В.
Belarus
rutkevitch@inbox.ruChumakA. G.ЧумакА. Г.
Belarus
rutkevitch@inbox.ruBelarusian State UniversityБелорусский государственный университетBelarusian State Medical UniversityБелорусский государственный медицинский университет16022025111230631909052025Copyright ©; 2025, Russian Academy of SciencesCopyright ©; 2025, Российская академия наук2025Russian Academy of SciencesРоссийская академия наукhttps://transsyst.ru/0869-8139/article/view/679311

Experiments were performed under urethane anesthesia on sexually mature non-pregnant female rats (n = 36). Pattern of electrical activity of the uterus in different phases of the estrous cycle, determined by the vaginal cytology (staining by Romanovsky dye), was studied. Electrohysterograms from the middle third of the left horn of the uterus were recorded using pressure bipolar electrodes. Increased excitability and conductivity of the uterus smooth myocytes occur during the stages of proestrus, estrus and metestrus, and their suppression is observed in diestrus. The maximum amplitude of motor potentials, compared to diestrus, was detected at the pro- (174 ± 17 μV) and metestrus (202 ± 20 μV) stages, while their mean frequency was high at the metestrus [4.4 (4.0; 5.0) Hz] and estrus [4.0 (4.0; 5.0) Hz)], exceeding those indicators for diestrus (86 ± 9 μV and 1.9 (1.3; 3.2) Hz approximately twice. Burst phase duration [40 (32; 50) and 36 (28; 47) s] of uterus periodic electrical activity had it maximum while rest period had it minimum [46 (40; 55) and 42 (26; 84) s] at proestrus and estrus stages which is also reflected in the high values of duty cycle – 0.46 (0.43; 0.50) and 0.45 (0.26; 0.63), respectively. Similar indicators for the diestrus stage were 27 (22; 32) and 80 (58; 124) s, 0.27 (0.18; 0.34). It is assumed that the highest excitability of the myometrium and its rhythmogenic areas during the metestrus stage, an increase in myometrium’s excitation conduction rate during proestrus and estrus, are due to an increase of electrical coupling between uterus smooth muscle cells.

В острых, проведенных под уретановым наркозом опытах на половозрелых небеременных самках крыс (n = 36) изучен паттерн электрической активности матки в разные фазы эстрального цикла, определяемые по цитологической картине окрашенных красителем Романовского вагинальных мазков. Регистрацию электрогистерограмм проводили при помощи прижимных биполярных электродов (отведение от средней трети левого рога матки). Повышение возбудимости и проводимости гладких миоцитов матки приходится на периоды проэструса, эструса и метэструса, а их угнетение наблюдается в диэструс. Максимальная по сравнению с диэструсом амплитуда моторных потенциалов была выявлена на стадии про- (174 ± 17 мкВ) и метэструса (202 ± 0 мкВ), а их частота – на стадиях метэструса [4.4 (4.0; 5.0) Гц] и эструса [4.0 (4.0; 5.0) Гц], в среднем двукратно превышая аналогичные показатели для диэструса (86 ± 9 мкВ) и 1.9 (1.3; 3.2 Гц). Для стадий проэструса и эструса длительность залпов потенциалов была максимальной [40 (32; 50) c] и [36 (28; 47) с], а периода покоя – минимальной [46 (40; 55)c] и [42 (26; 84) с], что находит свое отражение в высоких значениях коэффициента заполнения периода, равного 0.46 (0.43; 0.50) и 0.45 (0.26; 0.63) соответственно. Аналогичные показатели для стадии диэструса составили 27 (22; 32) и 80 (58; 124) с, 0.27 (0.18; 0.34). Предполагается, что наибольшая возбудимость миометрия и его ритмогенных областей в период метэструса, увеличение скорости проведения возбуждения в миометрии в проэструс и эструс происходит за счет увеличения степени электрической сопряженности составляющих его клеток.

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