Hyperlipidemia is an important risk factor for atherosclerosis and is frequently seen in patients with erectile dysfunction (ED). This study was designed to evaluate whether the acute effect of native low-density lipoprotein (nLDL) on intracavernosal pressure (ICP) is reversible and related to plasma asymmetrical dimethylarginine (ADMA), endogenous inhibition of endothelial nitric oxide synthase (eNOS) levels and eNOS expression in cavernous tissues. Hyperlipidemia was induced by a single dose of intravenous 4 mg kg(-1) nLDL. Experiments were performed 72 h (72H), 2 weeks (2W) and 8 weeks (8W) after nLDL injection. Endothelium-dependent relaxations, the ratio of ICP to mean arterial pressure (MAP; ICP/MAP), plasma ADMA levels and eNOS mRNA and protein levels were evaluated. The ICP/MAP ratio decreased in both the 2W and 8W groups. Endothelium-dependent relaxation responses to acetylcholine in the rat thoracic aorta were damaged in the 8W group. Plasma ADMA levels increased in the 8W group. mRNA expression of eNOS decreased in a time-dependent manner, whereas the protein expression increased. These results suggest that acute nLDL injection-induced impairments in erectile functions during an 8-week period are irreversible and might be related to an increase in ADMA levels and changes in the regulation of the eNOS/NO pathway.International Journal of Impotence Research advance online publication, 16 March 2017; doi:10.1038/ijir.2017.5.
International journal of impotence research. 2017 Mar 16 [Epub ahead of print]
N Durmus, A Toylu, S Evcim, B C Soner, O Demir, E Kahraman, T Demir, B Irer, S Gidener, N Atabey, A Esen
Department of Pharmacology, Faculty of Medicine, Dokuz Eylul University, Izmir, Turkey., Department of Medical Biology, Faculty of Medicine, University of Akdeniz, Izmir, Turkey., Department of Pharmacology, Faculty of Medicine, University of University of Konya NE, Konya, Turkey., Department of Urology, Faculty of Medicine, Dokuz Eylul University, Balcova, Izmir, Turkey., Department of Medical Biology, Faculty of Medicine, Dokuz Eylul University, Balcova, Izmir, Turkey., Department of Endocrinology, Faculty of Medicine, Dokuz Eylul University, Balcova, Izmir, Turkey., Izmir Metropolitan Municipality Eşrefpaşa Hospital, Clinic of Urology, Izmir, Turkey.