[Contraction mechanism of smooth muscle cells and its relationship with penile erection].

Penile erectile dysfunction (ED) is ascribed to the contraction-relaxation imbalance of smooth muscle cells (SMC), the weakening of their diastolic function and the strengthening of their systolic function. The contraction-related signaling pathways, cell membrane ion channels and SMC phenotypes all participate in the regulation of their contraction and its malfunction may cause a variety of SMC-related diseases. The signaling pathways RhoA/Rock and Raf/MEK/ERK1/2 interact with each other, suppressing the expression of the RhoA protein or reducing the level of Rock2 phosphorylation, which may contribute to the treatment of ED. The poor performance of VDCC or TRPC is reckoned to be an important cause of hypertension- or diabetes-related ED. The expressions of CaV1.2, TRPC1 and TRPC4 can be upregulated by many pathological factors, which may enhance the contraction of SMCs. The pathogenesis of ED may be associated with the differentiation of the phenotypes corpus cavernosal SMCs. This review focuses on the recent progress in the studies of the relationship between SMC contraction and ED.