ABSTRACT
The uterus consists of luminal and glandular epithelium, connective tissue stroma and peripheral myometrium. The luminal epithelium and the stroma together comprise the endometrium. The tissues of the endometrium, as well as the myometrium, are regulated by estrogen and progesterone. Although work with the ERα knockout (αERKO) mouse has indicated that embryonic development of the uterus and other female reproductive organs does not require estrogen (Lubahn et al., 1993), postnatal differentiation, growth
and functional activity of the uterus during the juvenile period and adulthood are obligatorily dependent on estrogens, especially 17-β estradiol (E2). Similarly, progesterone (P) plays critical roles in the uterus during the estrous or menstrual cycles and during the establishment and maintenance of pregnancy (Lydon et al., 1995, 1996).
