Lactotransferrin is the major estrogen inducible protein of mouse uterine secretions.

Antibody to an estrogen inducible mouse uterine protein (Teng, C. T., Walker, M. P., Bhattacharyya, S. N., Klapper, D. G., DiAugustine, R. P., and McLachlan, J. A. (1986) Biochem. J. 240, 413-422) has been used to isolate cDNA to the messenger RNA. Analysis of the deduced primary structure and additional biochemical characterization indicates that the protein is lactotransferrin. An increase in the level of lactotransferrin mRNA of at least 300-fold can be induced in the mouse uterus by estrogen. In contrast, the mRNA is virtually undetectable in rat uterine tissue following estrogen administration. The estrogenic stimulation in mouse uterus contrasts with the known prolactin dependence in mammary gland.