Recent evidence indicates that endothelin-1 (ET-1) might be a principal vasoconstrictor in the penis. We report that ET-1 injection into the cavernous sinuses before erection sharply reduced the magnitude of subsequent erections. Corpus cavernosum pressure-to-mean arterial pressure ratios (CCP/MAP), with maximal ganglionic stimulation, were 0.62 +/- 0.05 before ET-1 injection and 0.31 +/- 0.05 after, indicating that ET-1 acted as a vasoconstrictor. When ET-1 was injected during a maximal neurally induced erection, the ability of ET-1 to attenuate subsequent erections was diminished (CCP/MAP 0.75 +/- 0.02 before ET-1, 0.61 +/- 0.03 after). At submaximal stimulation voltages, injection of ET-1 during erection also attenuated its vasoconstrictive effect. Similarly, when ET-1 was injected during erection induced by intracavernosal injection of the nitric oxide (NO) donor NOR-1, subsequent erections were not significantly suppressed (CCP/MAP 0.53 +/- 0.04 before ET-1, 0.45 +/- 0.04 after). These findings that ET-1-induced vasoconstriction is attenuated during erection are consistent with the hypothesis that NO mediates erection both by initiating pathways that cause smooth muscle relaxation and by inhibiting the vasoconstrictive actions of ET-1.
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http://dx.doi.org/10.1152/ajpregu.2001.281.2.R476 | DOI Listing |
J Sex Med
December 2024
The James Buchanan Brady Urological Institute and Department of Urology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, United States.
Background: Preservation of erectogenic nerves during radical prostatectomy (RP) is hampered by limited understanding of their precise localization, due to their complex, intertwined paths, and the inherent individual variations across patients. Because erection utilizes a subset of cavernous nerves (CNs) that in response to sexual stimuli reveal phosphorylation of neuronal nitric oxide synthase (nNOS) on its stimulatory site Ser-1412, we hypothesized that delineation of nerves containing phosphorylated (P)-nNOS on Ser-1412 would establish the location of functional erectogenic nerves within the periprostatic region.
Aim: To identify the distribution and quantity of functional erection-relevant ([P-nNOS]-containing) nerves in the periprostatic area and discriminate them among the CNs distribution.
Cureus
October 2024
Pediatric Surgery, All India Institute of Medical Sciences, Raipur, Raipur, IND.
Zoological Lett
September 2024
Department of Ecology and Vertebrate Zoology, Faculty of Biology and Environmental Protection, University of Łódź, 12/16 Banacha Str., Łódź, 90-237, Poland.
Tadpoles serve as crucial evidence for testing systematic and taxonomic hypotheses. Suctorial tadpoles collected in Guyana were initially assigned to Rhaebo nasicus through molecular phylogeny. Subsequent analysis of larval and adult morphological traits revealed synapomorphies within the clade encompassing R.
View Article and Find Full Text PDFJ Sex Med
December 2024
Department of Urology, First Affiliated Hospital of Anhui Medical University, 218 Jixi Road, Shushan District, Hefei City, Anhui Province, 230000, China.
Cureus
August 2024
Department of Urology, National and Kapodistrian University of Athens, Athens, GRC.
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