CONTROL OF PERIPARTAL COLLAGENOLYSIS IN THE HUMAN CHORION-DECIDUA

OBJECTIVE: This study was designed to observe the in vivo status of ch orion-decidua gene expression for some major metalloproteinases, an in hibitor (tissue inhibitor of metalloproteinase-1), and an activator (t issue plasminogen activator) and the hormone relaxin at accessible tim e points in the peripartal period. STUDY DESIGN: Chorion-decidua from patients at cesarean section with and without labor and after spontane ous labor and delivery was used for preparation of poly (A)(+) ribonuc leic acid and quantitative Northern analyses with a series of oligo an d complementary deoxyribonucleic acid probes. RESULTS: In the period d esignated as the period before parturition, relaxin and matrix metallo proteinase-1 (interstitial collagenase) gene expression were relativel y high, reflecting the controlled loss of amniotic collagen necessary for fetal membrane expansion without rupture as the uterine volume inc reases. When active labor has begun, but before delivery, matrix metal loproteinase-3 (stromelysin) and matrix metalloproteinase-9 (type V co llagenase) gene levels significantly increased. After normal spontaneo us labor and delivery, tissue plasminogen activator and tissue inhibit or of metalloproteinase-1 messenger ribonucleic acids significantly in creased, together with a marginally increased expression of the genes for matrix metalloproteinase-1, matrix metalloproteinase-2 (type IV co llagenase), and relaxin. CONCLUSION: The expression of the genes for s ome major collagenolytic enzymes, an inhibitor, activator, and relaxin in the chorion-decidua, is different at the different stages of partu rition.