- Down-regulated expression of A disintegrin and metalloproteinase with thrombospondin-like repeats-1 by progesterone receptor antagonist is associated with impaired expansion of porcine cumulus-oocyte complexes. Shimada, M., Nishibori, M., Yamashita, Y., Ito, J., Mori, T., Richards, J.S. Endocrinology (2004)