ACTA ENDOCRINOLOGICA (BUC)

Context. The inflammatory disorders of the urinary bladder represent one of the most frequent disorders associated with hormonal unbalances caused by menopause. The involvement of estrogens and mast cells in this complex mechanism mediated by neuro-hormonal pathway is well known, but the pathogenesis through which the hormonal deprivation is affecting the Estrogen Receptor expression and is predisposing to urinary bladder inflammatory changes is still argued. Objective. To determine the structural changes associated with surgically induced menopause, and the effect of estrogen replacement therapy (ERT) in the urinary bladder morphology, mast cell population and Estrogen Receptor (ERα) expression. Subjects and methods. The effect of ovariectomy and ERT was monitored by quantifying the number of mast cells and the structural changes that the urinary bladder suffers. By immunohistochemistry we assessed the changes of the Estrogen Receptor Alpha (ERα) expression in the urothelium and detrusor muscle. The study was carried out on ovariectomised female rats over a period of 42 days. Results. The main alterations associated with the hormonal deprivation were represented by the growth in number of the bladder mast cells, atrophy of the urothelium and amplification of the expression of ERα from the urothelium, but not from the detrusor muscle. ERT significantly decreased the tissue expression for ERα, reduced the severity of bladder atrophy and the number of mast cells. Conclusions. The estrogenic hormonal substitution can diminish the severity of the atrophic, inflammatory and ERα changes in bladder disorders associated with ovarectomy in rat.