Investigation of Hydrogen Sulfide Therapy as a Strategy to Preserve Erectile Health During Androgen Deprivation

Abstract

Severe erectile dysfunction is prevalent in men with prostate cancer that undergo androgen deprivation therapy (ADT). Androgen deprivation drives drastic changes in the erectile tissues of the corpus cavernosum and pre-penile arteries, which include endothelial dysfunction, vascular remodeling, and diminished vascular smooth muscle quality. Restorative therapies are desperately needed to preserve tissue function and quality during the ADT period. Hydrogen sulfide (H2S) is a gaseous cell signaling molecule with vasodilatory, antioxidant, and anti-inflammatory properties that promote endothelial and vascular health. Recent advancements suggest that H2S may influence cellular health through stimulation of autophagy and regulation of mitochondrial dynamics. Therefore, the objective of this study was to investigate the ability of SG1002, an H2S pro-drug, to preserve erectile function following prolonged ADT. We hypothesized that SG1002 would have a positive effect on erectile function associated with a stimulation of protective pathways related to cellular antioxidant defense, mitochondrial fusion, and autophagy in the corpus cavernosum. Male C57Bl/6 mice were divided into four cohorts, one cohort that underwent sham castration surgery and three cohorts that underwent castration. Castrations were performed at 14 weeks of age. The sham group and one castrated cohort were placed on a control diet. The other two cohorts were placed on identical diets at the time of castration that were supplemented with SG1002 at approximately 20 mg/kg/day or 100 mg/kg/day. Mice were studied 5 weeks following surgery. Erectile function was assessed in vivo by measurements of intracavernous pressure (ICP) and mean arterial pressure (MAP) in response to stimulation of the cavernous nerve. Relative content of 19 proteins in the corpus cavernosum tissue was determined by western blot. Group differences were determined by one-way or two-way ANOVA followed by Tukey’s post hoc test, with an α-level of 0.05. Erectile function was severely diminished among all castrated cohorts compared to sham mice (p<0.01). SG1002 administration elicited a modest but statistically significant augmentation of erectile function (p<0.05) that was equivalent between the two doses. Castration was associated with a significant decrease in the antioxidant proteins GCLC, SOD3, and TRX1, as well as the mediators of mitochondrial fusion MFN1 and MFN2, and the autophagy stimulatory protein ATG7 (p<0.05). There were no significant effects of SG1002 treatment on any of the proteins investigated. In conclusion, H2S therapy elicited a modest protective effect on erectile function that may have been mediated by its direct vasodilatory potential or neurological mechanisms. Further study will be needed to determine if any adverse structural changes associated with castration were affected by H2S therapy. Funding From the National Institutes of Health Grant numbers: R03DK131242 and R03DK131242-01S1. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.