Differential regulation of a low-molecular-weight protein in oviductal and uterine fluids by ovarian hormones.

Abstract

Uterine and oviductal fluids of intact estrous rabbits contain a low-molecular-weight protein, which assumes a cone-shaped profile upon polyacrylamide gel electrophoresis followed by a modified Amido Black staining and destaining procedure. This protein is under ovarian hormonal control. It disappears from both uterine and oviductal fluid following ovariectomy. In uterine fluid, it is strongly induced by exogenously administered progesterone and to lesser degree by estradiol-17². In contrast, in oviductal fluid, progesterone induction of the cone protein is very slight, whereas its induction by estrogen, although of lesser absolute magnitude than in uterine fluid, is far more significant than the effects of progesterone. Thus, the cone proteins in oviductal and uterine fluids are differentially responsive to these two ovarian hormones, estrogen being its prime inducer in oviductal fluid and progesterone its major inducer in uterine fluid. Neither the uterine nor the oviductal fluid cone proteins could be ...