Upregulation of L-type Ca2+ channel activity by the vdr agonist elocalcitol in human and rat bladder

Uncoordinated bladder myogenic activity leads to symptoms known as overactive bladder (OAB) syndrome. Human bladder contraction mainly depends on activation of calcium and on RhoA/Rho-kinase signaling. Elocalcitol (Elo) is a Vitamin D receptor (VDR) agonist inhibiting RhoA/Rho kinase signalling in rat and human bladder, shown to ameliorate OAB symptoms compared to placebo in a phase II clinical study. In human bladder smooth muscle cells, Elo induced a dose-dependent rapid increase in intracellular calcium. Elo is able to upregulate calcium entry.