Distribution patterns of matrix matalloproteinase-3(MMP-3) and collagen in the prostaglandin e1 (PGE1)misoprostol treated pregnant rat cervix.

Cervical ripening is a crucial process leading to delivery. In clinic the most common agent to trigger the cervical ripening is misoprostol which is a synthetic prostaglandin E1 analog. The connective tissue of the cervix uteri is a typical connective tissue consisting of collagen, elastin, proteoglycans and hyaluronic acid. The degradation of extracellular matrix (ECM) is very important in term, cervical ripening and dilatation. Matrix Metalloproteinases (MMPs) are thought to play a critical role in these events. MMPs which are members of endopeptidases have the capability to digest ECM proteins through enzymatic activity. 28 types of MMPs are defined at the present time. The sub group of stromelysins, which include MMP-3 are capable of degrading collagens. MMP-3 is considered to be a strong candidate as a key regulator enzyme in cervix uteri due to its effect on many ECM components. In our study, female and male Rattus norvegicus rats were used. Rats were kept in cages where female/male proportion was 2/1 for one night and next day vaginal smear was performed. Female rats with sperm positive smears were accepted to be on day 0 of pregnancy. For our study, 5 control groups were generated, in estrus cycle,12th, 16th, 20th days of pregnancy and post partum 0 day; and 8 experimental groups were generated on the 12th, 16th, 20th days of pregnancy and post partum 0 day using 1,5 and 3,0 ?g misoprostol treatment. In our study, whether prostaglandins affect the ECM structure via MMPs during pregnancy and remodelling at the rat cervix in term was studied. In order to perform this, the distributions of collagen type I and IV, which are extensively present in ECM, and MMP-3 were studied by means of immunohistochemistry in pregnant rat cervix which was exposed to misoprostol at various dosages. Moreover, ultrastructural changes were investigated by transmission electron microscopy (TEM). In conclusion, in our immunohistochemical results we observed that collagen I protein were expressed densely in lamina propria while it was weak around the surroundly muscle. In contrast, the expression of MMP-3 antibody were weak in lamina propria where it was intermediate and dense around the surrounding the muscle. Our TEM results revealed that the effect of low dosage misoprostol were more effective on fibril diameter, and on the distance between central and peripheral fibrils when compared to high dosage misoprostol. Key Words; Rat, Cervical ripening, MMP-3, collagen I, collagen IV, Misoprostol