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 nM 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 (p-MLC), and β-actin. Protein expression was quantitated by densitometry, followed by statistical analysis with β-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.