Immunohistochemical evaluation of leiomyoma tissue and normal myometrium in patients with uter-ine leiomyoma during hypo- and hyperestrogenic conditions caused by of use of gonadotropin-releasing hormone ana-logues

In study immunohistochemical an alysis of markers of proliferation, apoptosis, extracellular ma trix degradation, angiogenesis and steroid hormone receptors in myomatous tissue and myometrium was conducted in 62 patients with uterine leiomyomas during long-term and short-term correction of hormonal status by gosere line acetate. Studies have shown that pseudocapsule of fibroids at immunohistochemical level is unchanged myometrium. For le iomyoma tissue compared to myometrium were characteristic greater expression of steroid hormone receptors and aromatase, inhibition of apoptosis, greater expression of angiogenic factors compared to unchanged myometrium. Under the action of GnRH-a direct and medi-ated by reduction of estradiol occurred molecular changes, which cover almost all parts of th e pathogenesis of fibroids and include inhibition of expression of estrogen receptor and aromat ase synthesis, enhancing of e xpression of progesterone recep-tors, inhibition of proliferation and angi ogenesis, accelerated degradation of ECM. Under the influence of hyperestrogeny caused by flare-up effect of GnRH-a and direct peripheral effect of GnRH analogs progression of uterine leiomyoma pro-vides increased sensitivity of uterine myocyt es to ischemia. Despite the obvious role of antiapoptotic factor bcl-2 in the pathogenesis of uterine fibroids, short- and long-term hormonal treatment with GnRH-a does not lead to significant changes in its expression.