RESUMO
OBJECTIVES: To investigate the effects of estrogen, raloxifene, and levormeloxifene on the expression of Rho-kinase signaling molecules in urethral smooth muscle cells (USMCs). METHODS: USMCs were isolated from female rats. Expression of calponin and estrogen receptors α (ERα) was detected by immunofluorescence staining. Cells were treated with estrogen, raloxifene, or levormeloxifene at 0, 1, 10, and 100 nmol/L for 48 h and then processed for Western blotting with antibodies against RhoA, Rho kinase I and II (Rock-I and Rock-II), myosin light chain (MLC), phosphorylated MLC, and ß-actin. Protein expression was quantitated by densitometry, followed by statistical analysis with ß-actin as control. RESULTS: USMCs expressed calponin and ERα. Treatment of USMCs with estrogen, raloxifene or levormeloxifene resulted in decreased expression of RhoA, Rock-I, Rock-II, and p-MLC in a dosage-dependent manner. CONCLUSIONS: Estrogen, raloxifene, and levormeloxifene may affect urinary continence by inhibiting the expression of Rho-kinase signaling molecules.
