University of New Hampshire Scholars\u27 Repository
Abstract
To study dynamic in vivo biochemical changes within the corpus luteum (CL) during luteolysis, a physiological model mimicking the onset of natural luteolysis was established, in which sheep received sequential systemic pulses of PGF2alpha (20ug/min/lhr) at mid-luteal phase of the estrous cycle. We previously demonstrated that after one pulse of PGF2alpha, the protein levels of extracellular matrix (ECM) regulators, tissue inhibitors of metalloproteinases (TIMPs) -1 and -2 decreased dramatically within one hour of PGF2alpha infusion, while matrix metalloproteinase (MMP)-2 activity increased 4 hrs post infusion. In summary, the early and dramatic decrease in TIMP-1 and TIMP-2 proteins, accompanied by an increase in MMP-2 activity, indicate an extension and amplification by the second pulse of PGF2alpha on regulators of the ECM within the CL. These findings confirm a critical role for regulators of the ECM in mediating both structural and steroidogenic changes during physiological PGF2alpha-induced luteolysis in sheep. (Abstract shortened by UMI.)
