Volume 56, Issue 6, Pages 1067-1073 (December 2009) Platelet Cyclic Guanosine Monophosphate as a Biomarker of Phosphodiesterase Type 5 Inhibitor Efficacy in the Treatment of Erectile Dysfunction: A Randomized Placebo- Controlled Study  Vincenzo Mirone, Roberta d'Emmanuele di Villa Bianca, Emma Mitidieri, Ciro Imbimbo, Ferdinando Fusco, Paolo Verze, Dino F. Vitale, Raffaella Sorrentino, Giuseppe Cirino  European Urology  Volume 56, Issue 6, Pages 1067-1073 (December 2009) DOI: 10.1016/j.eururo.2009.09.031 Copyright © 2009 European Association of Urology Terms and Conditions

Fig. 1 Effect of vardenafil on platelet cyclic guanosine monophosphate (cGMP) in healthy volunteers. Platelet harvested from healthy volunteers prior to or 1h following the administration of vardenafil, 20mg, were challenged with diethylamine (DEA)-NONOate (1, 10, and 100μM). Platelet cGMP significantly increased in the vardenafil group (n=6; p=0.003). European Urology 2009 56, 1067-1073DOI: (10.1016/j.eururo.2009.09.031) Copyright © 2009 European Association of Urology Terms and Conditions

Fig. 2 Effect of vardenafil, 5mg, versus placebo. The production of cyclic guanosine monophosphate (cGMP) following stimulation in vitro with diethylamine (DEA)-NONOate (1, 10, and 100μM) was evaluated prior to or after 6 wk following the treatment with either (a) placebo or (b) vardenafil. (c) The same data were analyzed as area under the curve (AUC) and expressed as changes in AUC. The analysis demonstrates a significant increase (p<0.05) in platelet cGMP in the vardenafil group versus placebo. European Urology 2009 56, 1067-1073DOI: (10.1016/j.eururo.2009.09.031) Copyright © 2009 European Association of Urology Terms and Conditions

Fig. 3 International Index of Erectile Function (IEF), sexual encounter profile (SEP). (a) IIEF and (b) SEP were significantly increased after 6 wk of treatment with either placebo or vardenafil, 5mg. However, the δ increase, calculated as the difference between the effect prior to and after the treatment, in (c) IIEF and (d) SEP were not significantly different between placebo and vardenafil. European Urology 2009 56, 1067-1073DOI: (10.1016/j.eururo.2009.09.031) Copyright © 2009 European Association of Urology Terms and Conditions

Fig. 4 isual sexual stimulation (VSS)-Rigiscan. VSS-Rigiscan data were calculated as the maximum rigidity achieved and expressed as a percentage. (a) Placebo did not cause any significant increase in VSS-Rigiscan response after 6 wk of treatment. Conversely, (a) vardenafil treatment caused a significant increase in the response. (b) The δ increase in VSS-Rigiscan response, calculated as the difference between the effect prior to and after the treatment, was significantly different between the placebo and the vardenafil group. European Urology 2009 56, 1067-1073DOI: (10.1016/j.eururo.2009.09.031) Copyright © 2009 European Association of Urology Terms and Conditions

Fig. 5 Vasodilator-stimulated phosphoprotein (VASP) and phosphorylated (p)-VASP evaluation in platelets. (a) A representative western blot for VASP and p-VASP. (b) Densitometric analysis shows a significant (p<0.01) change in the VASP–p-VASP ratio following the 6 wk of treatment with vardenafil versus placebo as opposed to the acute treatment in healthy volunteers. NS=not significant. European Urology 2009 56, 1067-1073DOI: (10.1016/j.eururo.2009.09.031) Copyright © 2009 European Association of Urology Terms and Conditions