1. Department of Nuclear Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50937, Cologne, Germany
2. Organic Chemistry, Bergische Universität Wuppertal, 42119 Wuppertal, Germany
3. Clinic and Polyclinic for Urology, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50937 Cologne, Germany
4. Institutes I & II of Pharmacology, Center of Pharmacology, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50931 Cologne, Germany