No abstract

We investigated the influence of the extracellular nitric oxide (NO) level on male copulatory behavior. We confirmed the changes of nitrite ([Formula: see text]) and nitrate ([Formula: see text]) in the medial preoptic area (MPOA) by administration of the NO precursorl-arginine (l-Arg, 10 mM) or the NO synthase inhibitor N G-monomethyl-l-arginine (l-NMMA, 10 mM) via a dialysis probe. [Formula: see text] and[Formula: see text] were measured simultaneously by an in vivo microdialysis method coupled with the Griess reaction.l-Arg induced significant elevations of extracellular [Formula: see text]and [Formula: see text].l-NMMA significantly reduced[Formula: see text] and[Formula: see text] levels. We observed male copulatory behavior during infusion ofl-Arg orl-NMMA. The mount rate of male rats significantly increased during infusion ofl-Arg in the MPOA. Administration of l-NMMA reduced the mount rate. These findings suggested that the elevation of extracellular NO in the MPOA facilitates male copulatory behavior of rats, whereas the decrease of NO reduces their copulatory behavior.

Abbreviations & AcronymsObjective: To comprehensively analyze the 5-year outcomes of tamsulosin treatment for patients with benign prostatic hyperplasia. Methods: Tamsulosin (0.2 mg/day) was given to 112 patients who had International Prostate Symptom Scores Ն8. They were prospectively followed for 5 years with periodic evaluation. If tamsulosin had to be discontinued, the reason was determined. Treatment failure was considered in the case of disease progression (postvoid residual urine volume Ն200 mL, acute urinary retention, febrile urinary tract infection or hydronephrosis as a result of bladder outlet obstruction), conversion to other a1-blockers or need for surgery. An intention-to-treat analysis was carried out. Results: A total of 34 patients (30.4%) continued the same medication for the overall study period, whereas 78 patients (69.6%) discontinued the medication. International Prostate Symptom Scores, Benign Prostatic Hyperplasia Problem Index and Quality of Life Index were significantly improved over the 5-year period. Treatment failure was observed in 21 patients (18.8%). Baseline prostate volume and postvoid residual urine volume were independent factors to predicting treatment failure. A total of 21 patients (18.8%) discontinued tamsulosin because of an improvement of symptoms. They were younger and had lower prostate-specific antigen levels than the remaining 91 patients. Their symptoms were stable even 1 year after termination of therapy. Conclusions: Long-term efficacy of tamsulosin was observed, although only a small portion of patients continued the treatment. a1-blocker monotherapy might be not appropriate for achieving a good long-term outcome in patients with a large prostate volume and a large amount of postvoid residual urine volume. Persistent improvement of symptoms, even after termination of tamsulosin, was observed in young patients with low prostate-specific antigen levels.

Altered NO levels in the PVN affected the frequency of reflexive erections, but not the mount rate. These studies contrast with previous observations of the effects of altered NO levels in the MPOA, and support the hypothesis that physiological specificity in the actions of NO on discrete brain nuclei may have important implications to erectile physiology and dysfunction.