Matrix metalloproteinase system is involved in cardiac extracellular matrix remodeling during pregnancy and postpartum (1152.1)

Matrix metalloproteinases (MMPs) and their natural inhibitors, the tissue inhibitors metalloproteinases (TIMPs) are the principle enzymes that regulate collagen remodeling, and play an important role in the determination of the collagen architecture of the tissue. Collagens (Col) are the most abundant proteins of the extracellular matrix (ECM) and the major structural component of connective tissues. The contribution of MMPs to heart remodeling during pregnancy and postpartum is not well defined. In the present study, we investigated changes in fibrosis, MMPs (MMP ‐1, ‐2 and ‐9) and TIMP‐1, along with Col (Col ‐I and III) expression during late pregnancy (21 days) and postpartum (7 days) in rat heart. Col ‐I and ‐III mRNA and protein expression increased during pregnancy and decreased to basal levels after 7 days of postpartum in left and right ventricle, respectively. Moreover, TIMP‐1 protein expression also increased during pregnancy and decreased in postpartum, while MMPs expression decreased in pregnancy. Results suggest that MMP system contribute to remodeling of cardiac extracellular matrix during pregnancy and postpartum in rats.