Meeting Abstract
Classical estrogen effects occur via nuclear receptors, but many known effects of estrogen are inconsistent with classical pathways. Recently, research has focused on non-genomic rapid effects of estrogen, mediated by receptors in the plasma membrane and second messengers. An experiment was conducted to determine if estrogen initiates rapid signaling events in the ovine endometrium by examining the effects of 17β-estradiol on the activation of phosphatidylinositol hydrolysis (PIP2/DAG pathway). Endometrial tissue was collected from four Polypay ewes on day 8 of the estrous cycle and incubated with tritium-labeled myo-inositol for 90 minutes followed by treatment with 17β-estradiol (10 nM) or vehicle for an additional 30 minutes. Statistical analysis revealed a significant activation of the PIP2 pathway by 17β-estradiol, evidenced by an increase in the incorporation of tritium-labeled myo-inositol into inositol phosphates. These preliminary data suggest rapid actions of estrogen may be mediated by activation of the PIP2 signaling cascade via estrogen receptors in the plasma membrane.
