著者

寿田 鳳輔 藤井 久四郎 新井 和夫 丸岡 利市 斎藤 仁隆

出版者

Japan Society of Smooth Muscle Research

雑誌

日本平滑筋学会雑誌 (ISSN:03743527)

巻号頁・発行日

vol.4, no.2, pp.191-202, 1968

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The spontaneous and oxytocin induced electrical activity of the pregnant uterus of rat has been studied <I>in vivo</I> by recording electromygorams at various stages during pregnancy. The electrical activity has been compared at different uterine portions in the pregnant uterus of rat; at the myometrium of the corpus, the cervix, the edge of the placental area, and the placental area. Also, one or two electrodes (silver wire, 50μ in diameter) were introduced into the myometrial coat at the different uterine poitions for the recording as described in the previous report. The experiments were performed on the 12th, 13th, 14th, 18th and 21st days of pregnancy. The electrical activity of the pregnant rat uterus consisted of repetitive spike discharges at the different uterine portions through various stages of pregnancy. <I>In vivo</I>, myometrium of the placental area showed a little spontaneous activity before term, but there was no difference between the myometrium of the edge of the placental area and of the other portions (the corpus and the cervix). No distinction between the electrical excitability of placental and nonplacental myometrium was observed at term. After the above control records were taken, oxytocin was injected in a dose of 2 or 3 i.u. intraumuscularly and the response in increase of spike discharges at the different uterine portions were clearly detected.

著者

寿田 鳳輔 藤井 久四郎 新井 和夫 丸岡 利市 斎藤 仁隆

出版者

Japan Society of Smooth Muscle Research

雑誌

日本平滑筋学会雑誌 (ISSN:03743527)

巻号頁・発行日

vol.4, no.1, pp.37-45, 1968

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Albino rats of Wistar strain with normal sexual cycle on the basis of their vaginal smears were used and anesthetized with Mintal (pentobarbital) injecting 5 mg/100 g intraperitoneally in acute experiments. Spontaneous electromyographic activity of the rat uterus <I>in vivo</I> was recorded using a concentric electrode (silver wire, 50μ diameter). One electrode was placed in the tubal side and the other electrode in the cervical side of a corpusuteri of the rat. Electromyographic recordings were made with a 2 channel inkwritingapparatus. The spontaneous electrical activity of the rat uterus <I>in situ</I> could be observed through the cycle. The basic electromyographic patterns of the nonpregnant ratuterus at the estrus were the train of spike and the spike burst. From proestrus to estrus, the spontaneous spike discharges increased in amplitude and in frequency and became of a set of their discharges. In some cases the spontaneous spike discharges were observed sporadically at the diestrus of the cycle and the castrated condition.