OXYTOCIN RECEPTORS AND PARTURITION IN THE GUINEA-PIG
OXYTOCIN RECEPTORS AND PARTURITION IN THE GUINEA-PIG
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DOI：
10.1093/biolreprod/22.5.1106
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发表时间：
1980-01-01
影响因子：
3.6
通讯作者：
SOLOFF, MS
中科院分区：
文献类型：
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作者：
ALEXANDROVA, M;SOLOFF, MS
大鼠分娩前，子宫肌层中催产素 (OT) 和雌二醇 17.β 受体的浓度突然升高。 (E)。这些增加对应于血浆孕酮 (P) 浓度的降低。由于豚鼠的血浆 P 浓度在产前没有下降，因此确定了该物种在足月前 OT 和 E 的子宫肌层受体浓度是否升高。豚鼠子宫中每个子宫肌层细胞的 OT 受体浓度在妊娠期间上升，并且从第 60 天到约 10 天达到最大。产后 12 小时（约第 69 天）。 OT 受体水平在产后第二天急剧下降。 OT 受体浓度的这些变化与先前发表的豚鼠子宫肌层对 OT 敏感性的变化相对应。子宫肌层核部分中 E 受体/mg DNA 的浓度在妊娠第 50 天期间没有变化，并且与 OT 受体浓度一样，从第 60 天到大约 10 天升至最大值。产后12小时。产后 60 天至 12 小时，个体动物中核 E 受体的浓度与 OT 受体的浓度成正比。相反，细胞质中E受体的浓度与OT受体的浓度之间没有明显的关系。尽管血浆 P 水平在整个妊娠期间保持较高水平，但血浆 E 与 P 的比率以及血浆 E 浓度在妊娠期间第 50-60 天达到最大，随后核 E 和 OT 受体浓度达到最大值。由于 E 与 P 的比率主要受血浆 E 浓度的影响，因此 E 水平的增加可能会刺激受体浓度的增加。尽管分娩前血浆 P 水平没有下降，但豚鼠与大鼠相似，子宫肌层中 OT 受体和核 E 受体的浓度有所增加。两个物种中 OT 受体浓度的增加对应于子宫肌层对 OT 敏感性的变化。这两个物种的不同之处在于，大鼠子宫肌层中 OT 受体浓度的突然增加似乎是分娩的可垂直触发因素，而在豚鼠中，OT 受体浓度升高到最大水平。分娩前 9 天似乎对 OT 引产具有许可作用。
Parturition in the rat is preceded by an abrupt rise in the concentration of myometrial receptors for oxytocin (OT) and estradiol-17.beta. (E). These increases corresponded to a decrease in plasma progesterone (P) concentrations. Because there is no prepartum decline in plasma P concentrations in the guinea pig, it was determined whether the concentrations of myometrial receptors for OT and E are elevated before term in this species. The concentration of OT receptors per myometrial cell in the guinea pig uterus rose during gestation and was maximal from Day 60 to .apprx. 12 h after parturition (about Day 69). OT receptor levels then fell sharply by the 2nd postpartum day. These changes in OT receptor concentration correspond to previously published changes in the sensitivity of the guinea pig myometrium to OT. The concentration of E receptors/mg DNA in the nuclear fraction of the myometrium was unchanged during the 1st 50 days of gestation and, like OT receptor concentrations, rose to a maximum from day 60 to .apprx. 12 h after parturition. The concentration of nuclear E receptors in individual animals was directly proportional to the concentration of OT receptors from day 60 to 12 h postpartum. In contrast, there was no apparent relationship between the concentration of E receptors in the cytosol and OT receptors. Although plasma P levels remained high throughout gestation, the ratios of plasma E to P, as well as plasma E concentrations were maximal during pregnancy on days 50-60, before the maxima in nuclear E and OT receptor concentrations were reached. Because the ratio of E to P was influenced primarily by plasma E concentration, it is possible that increases in E levels stimulate the increases in receptor concentrations. Despite the absence of a fall in plasma P levels prior to parturition, the guinea pig resembles the rat in that there were increases in the concentration of OT receptors and nuclear E receptors in the myometrium. The increases in OT receptor concentration in both species correspond to changes in the myometrial sensitivity to OT. The 2 species differ, in that the sudden increase in OT receptor concentration in the rat myometrial appears to be the vertitable trigger for parturition, whereas in the guinea pig the elevation of OT receptors to maximal levels .apprx. 9 days before parturition appears to have a permissive role in OT-induced labor.