No abstract

Western blot data were consistent with the hypothesis that the extracellular segment of TGF-alpha is cleaved from the transmembrane precursor in vivo, as has been demonstrated in other tissues. Immunohistochemistry demonstrated that the TGF-alpha antigens are concentrated in the luminal surface epithelium and decline and disappear in the early to midsecretory phase. These findings suggest that the most active period of membrane-bound TGF-alpha cleavage corresponds with the interval during which preimplantation embryos are in the uterine cavity.