EXPRESSION OF TISSUE INHIBITOR OF METALLOPROTEINASE-1 PROTEIN AND MESSENGER-RIBONUCLEIC-ACID BY THE OVIDUCT OF CYCLIC, EARLY-PREGNANT, AND OVARIECTOMIZED STEROID-TREATED GILTS

It has been suggested that tissue inhibitor of metalloproteinases (TIM P)-1 has a role in reproductive tissues, regulating tissue remodeling or enhancing embryonic development. Oviductal TIMP-1 mRNA levels and p rotein expression were examined in gilts during the estrous cycle and early pregnancy and in steroid-treated ovariectomized (OVX) gilts by e xplant culture, two-dimensional SDS-PAGE and fluorography, dot-blot hy bridization, immunoblot analysis, RIA, and immunocytochemical studies. TIMP-1 mRNA levels in the oviduct during the estrous cycle were great er (p < 0.02) on Days 2, 15, and 18 than on other days examined, and a nalysis of oviductal functional segments indicated an effect of day (p < 0.003), an effect of segment (p < 0.007), and a day x segment effec t (p < 0.03). The level of TIMP-1 mRNA was greater (p < 0.003) in the isthmus (I) on Day 2 than in the ampulla (A) or infundibulum (INF) or on other days examined (0 and 12). In steroid-treated OVX gilts, an ef fect of treatment with estradiol valerate (EV) + progesterone (P-4) wa s shown with increased (p < 0.003) TIMP-1 mRNA levels. De novo synthes is of TIMP-1 protein was found throughout the estrous cycle and early pregnancy in all functional segments, but protein expression was great er in the I and greatest on Day 2. In steroid-treated OVX gilts, TIMP- 1 protein synthesis was greatest in the I regardless of treatment, but with increased intensity after EV+P-4 treatment. TIMP-1 protein was f ound in oviductal flushings during the estrous cycle and early pregnan cy, and in steroid-treated OVX gilts regardless of day, status, or tre atment. Differences in TIMP-1 concentrations in oviductal fluid were f ound by day (p < 0.001), with breed differences detected between the M eishan and standard Western breeds. TIMP-1 protein was immunolocalized primarily to luminal epithelium of the INF, A, and I on all days of t he estrous cycle and early pregnancy and to some cells in the stroma a nd blood vessel walls. Staining intensity correlated with TIMP-1 prote in levels in oviductal flushings. The role of TIMP-1 in the oviduct re mains to be established.