[Morphometric analysis of gap junctions of the cell membrane in human uterine smooth muscle at term].
OBJECTIVE
To study the changes of the gap junctions (GJS) in the uterine smooth muscle cells at various stages of labor, and its relationship with the onset of labor.


METHODS
18 women (38 to 41 gestational weeks) were divided into three groups: not-in-labor, pre-labor, active in labor and six cases in each group. The uterine myometrium tissues were observed by transmission electron microscopy (TEM) and lanthanum tracing method.


RESULTS
The lengths and areas of GJS in uterine corpus and lower segment in the active in labor group were significantly larger than that of the other 2 groups, but there was no significant difference between the not-in-labor and pre-labor groups. The area but not the lengths of GJS in corpus was significant larger than that in the lower segment in the active in labor group.


CONCLUSIONS
The great increase of length and areas of GJS in all parts of the uterine smooth muscle was closely correlated with onset of labor.
Zhang
W
W
Xiang Ya Hospital of HuNan Medical University, Chang Sha.
Liu
J
J
Zeng
Q
Q
D000328:Adult; D005260:Female; D017629:Gap Junctions / Q000648:ultrastructure*; D006801:Humans; D007745:Labor Onset; D009130:Muscle, Smooth / Q000648:ultrastructure*; D009215:Myometrium / Q000648:ultrastructure; D011247:Pregnancy; D011263:Pregnancy Trimester, Third; D014590:Uterine Contraction; D014599:Uterus / Q000648:ultrastructure