caa a22 4500 475742478 CHVBK 20180406123503.0 cr unu---uuuuu 170329e20001201xx s 000 0 eng 10.1007/s002400000141 doi (NATIONALLICENCE)springer-10.1007/s002400000141 Determination of nitric oxide metabolites by means of the Griess assay and gas chromatography-mass spectrometry in the cavernous and systemic blood of healthy males and patients with erectile dysfunction during different functional conditions of the penis [Elektronische Daten] [A. J. Becker, S. Ückert, D. Tsikas, H. Noack, C. G. Stief, J. C. Frölich, G. Wolf, U. Jonas] Recent research implicated that the relaxation of cavernous arterial and trabecular smooth muscle - the crucial event in penile erection - is initiated by the release of nitric oxide (NO) from nerve terminals within the cavernous tissue as well as from the endothelia that line the lacunar spaces and the intima of penile arteries. The present study was undertaken to determine whether plasma levels of the NO metabolites nitrate (NO− 3) and nitrite (NO− 2) in the systemic and cavernous blood of male subjects change during different penile conditions, and whether there is a difference in the NO− 3 and NO− 2 levels of normal males and patients with erectile dysfunction (ED). Twenty-four potent adult male volunteers and 15 patients with ED were exposed to visual and tactile erotic stimuli in order to elicit penile tumescence and, in the group of healthy volunteers, rigidity. Whole blood was aspirated from the corpus cavernosum and the cubital vein, and NO− 3 and NO− 2 levels were determined in plasma aliquots by means of the Griess reaction and a method combining gas chromatography and mass spectrometry (GC-MS). The mean systemic and cavernous plasma NO3 −/NO2 − level in blood samples obtained from the healthy volunteers was 25-31 μM when determined by means of the Griess reaction and 37-41 μM when measured by GC-MS. Both approaches revealed that NO3 −/NO2 − levels in the peripheral and cavernous blood do not change appreciably during developing erection, rigidity and detumescence. Moreover, no significant differences were found between NO3 −/NO2 − plasma levels in the systemic and cavernous blood samples taken from the normal subjects and patients during penile flaccidity, tumescence and detumescence. Our results may reflect the fact that NO metabolism in the corpora cavernosa in the phases of penile tumescence and rigidity may account for only a minor fraction of local levels of NO3 − and NO2 −, which may also derive from exogenous sources. Moreover, the basal levels of NO metabolites in the blood flushing the lacunar spaces of the cavernous body in the state of developing erection could conceal any release of NO that may occur within the penile tissue. Thus, we conclude that the quantification of NO metabolites by means of advanced detection methods, such as GC-MS, is of no use in the workup of ED. Springer-Verlag Berlin Heidelberg, 2000 Key words Nitric oxide metabolites nationallicence Erectile dysfunction nationallicence Griess reaction nationallicence Gas chromatography nationallicence Mass spectrometry nationallicence Becker A. J. Department of Urology, Hannover Medical School, 30625 Hannover, Germany, DE aut Ückert S. Department of Urology, Hannover Medical School, 30625 Hannover, Germany, DE aut Tsikas D. Department of Clinical Pharmacology, Hannover Medical School, 30625 Hannover, Germany, DE aut Noack H. Otto-von-Guericke University Magdeburg, Institute of Medical Neurobiology, 39120 Magdeburg, Germany, DE aut Stief C. G. Department of Urology, Hannover Medical School, 30625 Hannover, Germany, DE aut Frölich J. C. Department of Clinical Pharmacology, Hannover Medical School, 30625 Hannover, Germany, DE aut Wolf G. Otto-von-Guericke University Magdeburg, Institute of Medical Neurobiology, 39120 Magdeburg, Germany, DE aut Jonas U. Department of Urology, Hannover Medical School, 30625 Hannover, Germany, DE aut https://doi.org/10.1007/s002400000141 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s002400000141 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Becker A. J. Department of Urology, Hannover Medical School, 30625 Hannover, Germany, DE aut NATIONALLICENCE 700 1- Ückert S. Department of Urology, Hannover Medical School, 30625 Hannover, Germany, DE aut NATIONALLICENCE 700 1- Tsikas D. Department of Clinical Pharmacology, Hannover Medical School, 30625 Hannover, Germany, DE aut NATIONALLICENCE 700 1- Noack H. Otto-von-Guericke University Magdeburg, Institute of Medical Neurobiology, 39120 Magdeburg, Germany, DE aut NATIONALLICENCE 700 1- Stief C. G. Department of Urology, Hannover Medical School, 30625 Hannover, Germany, DE aut NATIONALLICENCE 700 1- Frölich J. C. Department of Clinical Pharmacology, Hannover Medical School, 30625 Hannover, Germany, DE aut NATIONALLICENCE 700 1- Wolf G. Otto-von-Guericke University Magdeburg, Institute of Medical Neurobiology, 39120 Magdeburg, Germany, DE aut NATIONALLICENCE 700 1- Jonas U. Department of Urology, Hannover Medical School, 30625 Hannover, Germany, DE aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer