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It is known that a proportion of patients who undergo transurethral resection of the prostate (TURP) will develop erectile dysfunction (ED). This study examined the incidence of ED after TURP using objective and subjective parameters and risk factors for the development of ED. All benign prostate hyperplasia (BPH) patients who were indicated for TURP had to meet the criteria of the International Index of Erectile Function (IIEF) 5 scores of more than 16, and with normal nocturnal penile tumescense (NPT) which had at least one episode of nocturnal erections with both base and tip rigidity exceeding 55% for at least 10 min. The patient's nocturnal erection were measured using Rigiscan, over two consecutive nights, approximately 3-4 days preoperatively and 3 months postoperatively. A total of 63 patients were eligible for the study; the mean age was 63.3 years (range 49-85 years). Nine (14%) patients were found to have postoperative ED. Patients who developed ED postoperatively had a lower IIEF-5 score and NPT parameters preoperatively (for all parameters, P<0.0001). For risk factors, diabetes mellitus were found to be a significant independent risk factor. The incidence of ED post-TURP using objective parameters was 14%. Without taking note of the risk factors, TURP is a safe procedure with regard to sexual function.

Cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) are important second messengers in mediating relaxation of various smooth-muscle cells. This second-messenger pathway also appears to be essential for cavernous smooth-muscle relaxation on the basis of the assumption it would be of theoretical and clinical interest to determine the functional relevance of various phosphodiesterase (PDE) isoenzymes in human cavernous smooth-muscle This study was concentrated on characterizing PDE isoenzymes that exist in cavernous smooth muscle and evaluating the effect of selective PDE inhibitors on relaxation that is needed for the initiation of erection. Separation of PDE isoenzymes was performed using anion-exchange chromatography [diethylaminoethanol (DEAE)-Sepharose column], and a modification of the PDE-assay method proposed by Thompson and Lakey was used. The relaxation effect of PDE inhibitors was evaluated in an organ-bath study. Three different PDE isoenzymes have been shown in human cavernous smooth-muscle homogenate: cGMP-inhibited PDE (PDE III), cAMP-specific PDE (PDE IV), and cGMP-specific PDE (PDE V). All PDE inhibitors tested showed a relaxation effect on isolated human cavernous smooth-muscle, albeit with differing potency. Quazinone (a selective PDE III inhibitor) had potency at least equal to that of papaverine (a non-selective PDE inhibitor) and had a superior effect as compared with Rolipram (a selective PDE IV inhibitor) and zaprinast (a selective PDE V inhibitor). The present study provides the rationale and opens the possibility of using selective PDE inhibitors in the treatment of patients with erectile dysfunction.

Summary. An increase in cyclic nucleotide monophosphate levels is suggested to play a prominent role in mediating smooth-muscle relaxation. Cyclic nucleotide phosphodiesterase (PDE) influences smooth-muscle tone by decreasing the level of cyclic nucleotides. At present, five different families of isoenzymes of PDE exist that show a distinct species-and organ-specific distribution. Our study was done to evaluate the existence of specific PDE isoenzymes and its functional role in human ureteral tissue. Normal ureteral tissue was homogenized and centrifuged and the supernatant fraction was separated using anioin-exchange diethylaminoethyl (DEAE)-Sephacel chromatography. A PDE assay was then performed and the peak fractions were added to different specific PDE activators and inhibitors. In vitro, longitudinal ureteral strips were precontracted and different selective and nonselective PDE inhibitors were added incremently. Three different PDE isoenzymes were characterized: PDE I (calmodulin-sensitive), PDE II (cGMP-stimulated), and PDE IV (cAMP-specific). All PDE inhibitors relaxed the strips dose-dependently, with the 50% effective concentrations (ECs0) being 30 gM for papaverine, 40 ~tM for zaprinast, 25 gM for quazinone, and 0.1 gM for rolipram. The ureter-relaxing effect of the PDE IV inhibitor at low concentrations, combined with its low-level effect on the systemic circulatory parameters, may open the possibility of using selective PDE IV-inhibitors in the treatment of ureteral colics or for ureteral stone passage.The incidence of urinary-tract stone disease in Germany is estimated to be 0.1%, with the prevalence for primary stones being 4%-5%. In the case of an uncomplicated renal or ureteral stone, the application of intravenous analgesics is the most useful means of relieving the pain [1,2]. With respect to the potential beneficial effect of ureteral relaxation on stone passage, some spasmolytic agents such as phentolamine and orciprenaline have been shown to dilate the ureteral lumen at the level of an artifi-