Kilarski W M, Rezapour M, Bäckström T, Roomans G M, Ulmsten U
Department of Cytology & Histology, Jagiellonian University, Krakow, Poland.
Acta Obstet Gynecol Scand. 1994 May;73(5):377-84. doi: 10.3109/00016349409006247.
In the human myometrium, the formation of gap junctions in the various stages of labor and, in correlation with the concentration of progesterone in the maternal blood, has not been described adequately. The accepted hypothesis that raised concentrations of progesterone in maternal blood in animals prevent the formation of gap junctions was scrutinized in human myometrium. Myometrial tissue was examined by electron microscopy for the presence of gap junctions and analyzed morphometrically in 17 women who had an elective or emergency cesarean operation at the 38th or 39th week of pregnancy. The concentrations of progesterone and estradiol in the maternal and cord blood was measured by means of radioimmunoassay. The frequency and area of gap junctions varied in relation to the presence or absence of labor. In the myometrium of women in labor, gap junctions were most frequent (5.2/1000 microns of cell membrane), their area largest (0.32 microns 2/1000 microns of cell membrane) and their fractional area greatest (0.20%). When the women were not in genuine labor or when contractions were weak, the percentage fractional areas of gap junctions were low (0.020-0.090) and the gap junctions very small. In the pre- and active phases of labor, the concentration of progesterone in maternal blood was significantly higher (p < 0.025 and 0.03 respectively) than in women who were not in labor. Hence, despite high concentrations of progesterone in the maternal and cord blood at term, the myometrium presented numerous gap junctions of relatively large area.
在人类子宫肌层中，尚未充分描述分娩各阶段缝隙连接的形成情况以及与母血中孕酮浓度的相关性。动物实验中母血中孕酮浓度升高会阻止缝隙连接形成这一公认假说，在人类子宫肌层中受到了审视。对17名在妊娠38或39周时进行择期或急诊剖宫产手术的女性的子宫肌层组织进行电子显微镜检查，以确定是否存在缝隙连接，并进行形态计量分析。通过放射免疫分析法测量母血和脐血中孕酮和雌二醇的浓度。缝隙连接的频率和面积因是否临产而异。在临产女性的子宫肌层中，缝隙连接最为频繁（每1000微米细胞膜有5.2个），其面积最大（每1000微米细胞膜0.32平方微米），其占比面积也最大（0.20%）。当女性未真正临产或宫缩较弱时，缝隙连接的占比面积百分比很低（0.020 - 0.090），且缝隙连接非常小。在分娩的前期和活跃期，母血中孕酮浓度显著高于未临产女性（分别为p < 0.025和0.03）。因此，尽管足月时母血和脐血中孕酮浓度很高，但子宫肌层仍呈现出大量面积相对较大的缝隙连接。
