| PrefaceLabor is a complex physiology course, its machenism is unknown. The traditional ideas were that the cervix was passive in the labor. Recently researchers think that it is also itself changes by a large number of research. The cervix is mainly composed of connective tissue, the content of collagen decides its toughness. The maturation and ripening of cervix was related with the degration of collagen, and MMPs played an important role in the degration of collagen. MMPs take part in the physiology courses of embryo growth, labor starting and so on. Our objective is to find the relation between MMPs and the maturation and ripening of cervix by determining the concentration of MMPs in the lower uterine tissues, provide theorical and ex-perimantal evidences for the research of labor starting.MaterialsWe divided 72 cases into two groups, 56 cases with uteral contractions and 16 cases without. Then we divided the former into 4 groups: 16 cases with ripening of the cervixes less than 3cm, 14 cases from 3cm to 5cm, 14 cases more than 5cm and other 12 cases havingentered the second stage of labor. Patients were informed in detail a-bout the aims and procedures of the study and gave their written consent. We measured the concentrations of MMP - 9 by ELJSA after their cesarean sections. Cervical dilatation was assessed by palpation immediately before surgery by an experienced obstetrician between contractions. Uterine biopsy specimens were excised with scissors by a standardized technique at cesarean section from the lower margin of the uterotomy wound in the midline immediately before closure. The specimens were washed in physiological saline solution. Part of each sample was immediately frozen in liquid nitrogen after extraneous, material had been removed and was stored at - 80 Tl until it was investigated for MMP-9.Methods1. Prepare all reagents, working standards and samples2. Dilute samples 32 fold3. Add 100 ul of Assay Diluent RD -34 to each well.4. Add 100 ul standard or sample per well, incubate for 2 hours at room temperature on a horizontal orbital microplate shaker set at 500 50rpm.5. Aspirate each well and wash for four times.6. Add 200ul of MMP -9 conjugate to each well, incubate for 1 hour at room temperature on the shaker.7. Repeat the wash for four times8. Add 200ul of substrate solution to each well, incubate for 30minutes, protect from light9. Add 50ul of stop solution to each well10. Determine the optical density of each well within 30 minutes, using a microplate reader to 450nm.Results1. There is no statistically significant difference among. different stage of the cervix ripening at age of patients, pregnancy term and baby weight.2. There is a significant difference between the group with contraction 3.05 2. 64 ng/mg and the without 0. 76 0. 43 ng/mg ( P<0.05).3. The concentration of MMP - 9 in the group without contraction is 0.76 0. 43 ng/mg, entered the first stage of labor 2. 23 2.02 ng/mg, entered the second stage of labor 6.08 2.53 ng/mg( P <0. 01). We found a significant difference among them.4. Within the labor having entered the first stage of labor, the bigger the cervix had ripened, the higher concentration of MMP - 9 we gained, but there was no significant difference among them.DiscussionThe cervix is composed of connective tissue, and its mainly content is collagen. Cervical softening during parturition is likely to involve breakdown of collagens, which, in turn, requires the presence of specific collagenases. After the middle term of pregnancy, collagenbunch began to break, the content reduced apparently. MMPs played an important role in the degration of collagen, lead to the maturation and ripening courses, for example embryo growth, labor starting and so on. There are type 1,2,3 ,8,9 in the cervix. Vadillo added anti -MMP - 9 into pregnant tissues, and found that the activity of MMPs could be inhibited to 50% , so they thought that MMP -9 play a main role in the labor starting. The c...
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