[RigiScan monitoring assists tadalafil medication in the treatment of penile ED].

OBJECTIVE: To investigate the application value of RigiScan monitoring in assisting tadalafil medication. METHODS: This self-control study included 89 ED patients (IIEF-5 < 21) treated in our hospital from August 2019 to July 2020. The patients underwent audiovisual sexual stimulation (AVSS), nocturnal penile tumescence and rigidity (NPTR) test, scoring on the Patient Health Questionnaire-9 (PHQ-9) and Generalized Anxiety Disorder 7-Item Scale (GAD-7), blood routine test, blood biochemical analysis, and hormone secretion examination, which confirmed 21 cases of psychogenic, 28 cases of organic and 40 cases of mixed ED. We treated the patients with tadalafil at 5 mg/d for 30 days, followed by examination of their erectile function by IIEF-5 scoring and AVSS and comparison of their erectile function with the baseline. For some of the patients that responded poorly to tadalafil at 5 mg/d, we increased the dose to 20 mg and detected the efficacy by AVSS at 1 h after medication. For those with organic or mixed ED irreponsive to tadalafil at 20 mg, we performed screening for corpora cavernosal venous leakage (CCVL) by intracavernosal injectionof alprostadil and penile color Doppler duplex ultrasonography or used dynamic infusion cavernosometry and cavernosography (DICC) to confirm the diagnosis of CCVL. RESULTS: The effectiveness rates of 5 mg/d tadalafil on mild, moderate and severe ED were 85.4%, 53.1% and 43.8%, respectively, significantly higher on mild than on moderate and severe ED (P = 0.002), and its effectiveness rates on psychogenic, organic and mixed ED were 90.5%, 60.7% and 57.5%, respectively, remarkably higher on psychogenic than on organic and mixed ED (P = 0.026). For those with organic or mixed ED irresponsive to 5 mg/d tadalafil, the increased dose of 20 mg achieved an effectiveness rate of 64.3%. (P = 0.033). The results of DICC did not encourage tadalafil medication for the cases of organic or mixed ED with CCVL irresponsive to both 5 mg and 20 mg tadalafil. CONCLUSION: RigiScan monitoring plays a guiding role in tadalafil medication of ED and helps distinguish organic from psychogenic ED. Tadalafil at 5 mg/d produces a better effect on mild than on moderate and severe ED, and so does it on psychogenic than on organic and mixed ED. The dose of medication can be increased to 20 mg for organic and mixed ED irresponsive to 5 mg tadalafil, but tadalafil is not recommended for organic and mixed ED with CCVL irresponsive to both 5 mg and 20 mg tadalafil.

Epigallocatechin-3-gallate ameliorates erectile function in aged rats via regulation of PRMT1/DDAH/ADMA/NOS metabolism pathway.

Aging-related ED is predominantly attributed to neurovascular dysfunction mediated by NO suppression and increased oxidative stress in penis. The alterations of protein arginine methyltransferases 1 (PRMT1)/dimethylarginine dimethylaminohydrolase (DDAH)/asymmetrical dimethylarginine (ADMA)/NO synthase (NOS) pathway regulate NO production in the vascular endothelium. Epigallocatechin-3-gallate (EGCG) is one of the most abundant and antioxidative ingredients isolated from green tea. In the present study, 40 Sprague-Dawley rats were randomly distributed into four groups: one young rat group and three aged rat groups treated with daily gavage feedings of EGCG at doses of 0, 10 mg kg-1 and 100 mg kg-1 for 12 weeks, respectively. Erectile function was assessed by electrical stimulation of the cavernous nerves with intracavernous pressure (ICP) measurement. After euthanasia, penile tissue was investigated using Western blot and ELISA to assess the PRMT1/DDAH/ADMA/NOS metabolism pathway. Superoxide dismutase (SOD) and malondialdehyde (MDA) levels were detected by colorimetry. We also evaluated smooth muscle contents. The ratio of maximal ICP and mean systemic arterial pressure (MAP) was markedly higher in EGCG-treated aged rats than in untreated aged rats. We found that DDAH1 and DDAH2 were expressed in cavernosal tissue, and they were downregulated in corpora of aged rats. The administration of EGCG upregulated the expression and activity of DDAH. In contrast, EGCG treatment downregulated the expression of PRMT1 and ADMA content. Moreover, EGCG-treated rats showed an improvement in smooth muscle expression, the ratio of smooth muscle cell/collagen fibril, SOD activity, and MDA levels when compared with untreated aged rats.

Probucol Improves Erectile Function by Restoring Endothelial Function and Preventing Cavernous Fibrosis in Streptozotocin-induced Diabetic Rats.

OBJECTIVE: To investigate the effects of probucol on erectile function in streptozotocin-induced diabetic rats and explore the underlying mechanisms. METHODS: A total of thirty 12-week-old Sprague-Dawley male rats received a 1-time intraperitoneal streptozotocin (60 mg/kg) or vehicle injection after a 12-hour fast. Three days later, the streptozotocin-induced diabetic rats were randomly divided into 2 groups and were treated with daily gavage feedings of probucol at doses of 0 and 500 mg/kg for 12 weeks. A positive control group underwent intraperitoneal injection of saline followed by daily gavage of saline solution. Erectile function was assessed by electrical stimulation of the cavernous nerves with real-time intracavernous pressure measurement. After euthanasia, penile tissue was investigated using immunohistochemistry, Western blot, and ELISA to assess the protein arginine-N-methyltransferase 1/dimethylarginine dimethylaminohydrolase/asymmetric dimethylarginine/nitric oxide synthase metabolism pathway. Superoxide dismutase activity and malondialdehyde levels were detected by colorimetry. We also evaluated penile histological changes such as smooth muscle contents and Masson's trichrome stain. RESULTS: Significant recovery of erectile function was observed in the probucol-treated rats than the untreated diabetic rats. The protein expression of dimethylarginine dimethylaminohydrolase and nitric oxide synthase, cyclic guanosine monophosphate concentrations, and superoxide dismutase activity in cavernous tissue of probucol-treated rats were significantly higher than the untreated diabetic rats. The protein expression of protein arginine-N-methyltransferase 1, asymmetric dimethylarginine concentrations, and malondialdehyde levels in cavernous tissue of probucol-treated rats were significantly lower than the untreated diabetic rats. In addition, probucol treatment markedly augments the cavernous smooth muscle content. CONCLUSION: Probucol treatment improves erectile function by restoring endothelial function and preventing cavernous fibrosis in streptozotocin-induced diabetic rats.