Degradation and reconstitution of extracellular matrix in uterine endometrium is a crucial event for embryonic implantation and is regulated by matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs). In the present study, we investigated the regulation of MMP and TIMP expression in cultured bovine endometrial stromal cells (BESCs) and a bovine trophoblast cell line BT-1 (BT-1 cells). The production of proMMP-9 was induced by transforming growth factor β (TGFβ) and 12-O-tetradecanoylphorbol 13-acetate in the stromal cells. The treatment of BESCs with TGFβ, insulin-like growth factor-I, and hepatocyte growth factor (HGF) resulted in a significant increase in the level of TIMP-1 in the culture medium. In addition, a significant increase of TIMP-2 production was observed in interleukin (IL)-1α and HGF-treated BESCs. However, the expression of TIMP-1 and TIMP-2 mRNA was not augmented by these factors. The treatment of BESCs with 12-O-tetradecanoylphorbol 13-acetate resulted in a significant increase in the level of TIMP-1 but a significant decrease in the level of TIMP-2 in the stromal cells. Membrane type-1 MMP mRNA expression in the stromal cells was augmented by tumor necrosis factor α (TNFα), IL-6, HGF, and 12-O-tetradecanoylphorbol 13-acetate. On the other hand, BT-1 cells constitutively produced proMMP-9 and proMMP-2, and the treatment of BT-1 cells with TNFα, HGF, and 12-O-tetradecanoylphorbol 13-acetate resulted in a significant increase in the level of proMMP-9 but not in the level of proMMP-2. The production of TIMP-1 in BT-1 cells was also augmented by IL-1α, TNFα, and HGF at the level of translation and was transcriptionally increased by 12-O-tetradecanoylphorbol 13-acetate. However, the level of TIMP-2 mRNA in BT-1 cells was not affected by any of the treatments. These results suggest that the expression of MMPs and TIMPs is differentially regulated by cytokines and growth factors and that the production of TIMP-1 and TIMP-2 may not be accompanied by changes in their mRNA expression in bovine endometrium and trophoblasts. Furthermore, as in humans and rodents, MMPs and TIMPs may contribute to the control of degradation and reconstitution of extracellular matrix in bovine endometrium during embryonic implantation and early placentation.