The Study Of Calcium Channel Blocker On The Function Of Unstable Detrusor Muscle

Backgroud and Objective: Detrusor instability (DI) is one of the most common micturational dysfuction in clinic, mainly appears to be urinary frequency, urinary urgency and stress urinary incontinence et al. Detrusor instability has features as variant etiologies, high incidence and poor treatment outcomes. Therefore, the further studies on the regulation of detrusor muscle function and pathogenesis of DI are necessary and significant. The etiological factors of DI are usually referred as bladder outlet obstruction (BOO), neurological dysfunction and idiopathic factors. Recently, although it has made a rapid progress in studying on pathogenesis of detrusor instability, the pathophysiology is still unclear. The main controversy is focused on whether it is neurogenic or myogenic causes.The latest accumulated evidences indicate that detrusor instability is closely related to the enhanced excitability of detrusor, the origin of detrusor instability is the increased excitability of detrusor smooth muscle cells, which is believed to be due to a myogenic alteration of excitability. When it comes to detrusor instability caused by neurogenic, obstructive and idiopathic factors, there has no more related literature whether they have some similarity in pathogenesis.The detrusor smooth muscle cell is a sort of excitable one, and the generation of its excitation is regulated by a variety of factors, among which the Ca2+ signal plays a key role.The premise of excitation of the detrusor smooth muscle cell is the influx of the extracellular Ca2+ ion, then leads to the alteration of the membrabe potential, and activates the voltage-gated ion channels, and results in the membrane depolarization simultaneously, other Ca2+-dependent ion channels and receptors also activated by Ca2+ ion, serving as a second messenger, jointly participate in the initiation of the action potential. The influx of Ca2+ ion into the cytoplasm is mainly controlled by way of the Ca2+ channels and there are dense L-type and T-type Ca2+ channels in the detrusor cell membrane. The objective of this study is to discuss the importance of the detrusor myogenic factors and the changes in function and quantity of calcium channels in the mechanism of DI .