Quercetin Relaxed the Smooth Muscle of Rabbit Penile Corpus Cavernosum by Activating the NO-cGMP Signaling Pathway

The aim of this study was to investigate the effect and action mechanism of quercetin on penile corpus cavernosum smooth muscle (PCCSM). PCCSM precontracted with phenylephrine (Phe) was treated with four different concentrations of quercetin (10−7, 10−6, 10−5 and 10−4 M). PCCSM were preincubated with N-Nitro-L-arginine methyl ester hydrochloride (L-NAME) and 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) to block nitric oxide synthase and guanylate cyclase, respectively. The changes in PCCSM tension were recorded, and cyclic nucleotides in the perfusate were measured by radioimmunoassay. The interactions of quercetin with phosphodiesterase type 5 inhibitors (PDE5-Is) such as sildenafil, udenafil and mirodenafil, were also evaluated. PCCSM relaxation induced by quercetin occurred in a concentrationdependent manner. The application of quercetin to PCCSM pre-treated with L-NAME and ODQ significantly inhibited the relaxation. Quercetin significantly increased cGMP in the perfusate. Furthermore, quercetin enhanced PDE5-Is-induced relaxation of PCCSM. Quercetin relaxed the PCCSM by activating the NO-cGMP signaling pathway, and it may be a therapeutic candidate or an alternative treatment for patients with erectile dysfunction who do not completely respond to PDE5-Is.

Feasibility study of transplantation of penile corpus cavernosum and major pelvic ganglion in renal subserous region / 北京大学学报(医学版)

Objective:To study the feasibility of transplantation of normal rat penile corpus cavernosum and major pelvic ganglion (MPG)into the renal subserous region of a Nu /Nu mouse based on allograft technology.Methods:Penile corpus cavernosum and MPG,harvested from Sprague-Dawley (SD)rats under sterile condition,were transplanted underneath the kidney capsule of Nu /Nu mice through the mi-crosurgery instruments and surgery microscope.The histopathologic changes and cellular proliferation in the transplanted penile corpus cavernosum and MPG were then analyzed at the end of 1week and 4 weeks after transplantation.Histological staining and immunohistochemical staining were used to evaluate the main outcome measures.Results:After 1 week,the tissue morphology of the transplanted corpus caverno-sum underneath the kidney capsule of Nu /Nu mice was consistent with normal penile corpus cavernosum, and blood could be observed in the penis cavernous sinus of the graft;after 4 weeks,the mophorlogy of the tranplanted corpus cavernosum near the kidney was consistent with normal penile corpus cavernosum, while fibrosis was noteworthy in the graft away from the kidney,but blood could still be seen in the penis cavernous sinus.After 1 week,the tissue morphology of the transplanted MPG was consistent with normal MPG,multiple islet-like cell clusters could be seen in the transplanted MPG in the renal subserous re-gion,and angiogenesis could be observed near the kidney;after 4 weeks,a network of blood vessels was clearly visible away from the kidney,and islet-like cell clusters were still clearly observed in the trans-planted MPG.In addition,ki67 positive cells were observed in the transplanted penile corpus cavernosum and MPG after 4 weeks of transplantation,which indicated that there was still cell proliferation activity in the grafts.Conclusion:The transplanted corpus cavernosum and MPG underneath the kidney capsule of Nu /Nu mice could survive at least 4 weeks.Moreover,the inner structure of the transplanted corpus ca-vernosum and MPG was close to the normal tissue.The underlining mechanism may be related to the lo-cal microenvironment underneath the kidney capsule of Nu /Nu mice and the neovascularization in the transplanted grafts.