No abstract

In functional arterial studies using wire myography, the determination of a vessel’s standardized normalization factor (factor k) is an essential step to ensure optimal contraction and relaxation by the arteries when stimulated with their respective vasoactive agents and to obtain reproducible results. The optimal factor k for several arteries have been determined, however, the optimal initial tension and factor k for the arteries involved in erection remains unknown. Hence, in the present study we set out to determine the optimal factor k for the internal iliac artery, proximal and distal internal pudendal artery (IPA), and dorsal penile artery. After isolating, harvesting, and mounting the arteries from male Sprague-Dawley rats on a multi wire myograph, we tested arterial responsivity to high K+-stimulation when the factor k was set at 0.7, 0.8, 0.85, 0.9, 0.95, 1.0, 1.1, and 1.2 to determine the factor k setting that results in the greatest K+-induced active force production for each vessel type. The data showed the optimal factor k is 0.90-0.95 for the dorsal penile, distal internal pudendal and internal iliac arteries while it is 0.85-0.90 for proximal internal pudendal artery. These optimal values corresponded to initial passive tension settings of 1.10±0.16 - 1.46±0.23, 1.28±0.20 - 1.69±0.34, 1.03±0.27 - 1.33±0.31, and 1.33±0.31 - 1.77±0.43 mN/mm for the dorsal penile, distal IP, proximal IP, and internal iliac arteries, respectively.

Erectile Dysfunction (ED) is the most common sexual dysfunction in men and is characterized by the inability to achieve or maintain an erection satisfactory for sexual intercourse. Normal erectile function is highly dependent on testosterone so any dysfunction in testosterone production may accelerate ED pathogenesis. Hypogonadism is a direct cause of ED and is characterized by the diminishing functionality of the testes in producing testosterone. Other pathological conditions such as obesity and diabetes, share similar complications of ED due to decreased testosterone levels. Furthermore, these conditions exhibit increased oxidative stress. Decreased testosterone can weaken antioxidant defenses and increase oxidative stress that then leads to endothelial dysfunction by reducing nitric oxide bioavailability and increasing fibrosis which ultimately leads to ED. Current therapies for ED do not directly target antioxidant defenses to reduce oxidative stress damage. Two prospective drugs, Resveratrol and Mitoquinone (MitoQ), have antioxidant properties that limit oxidative stress and may improve erectile function. They have shown to be successful in decreasing oxidative stress damage and improving endothelial function in cardiovascular disease models, so the objective of this study was to explore the effect resveratrol and MitoQ has on antioxidant defense gene expression and erectile function in a model of hypogonadism. We hypothesized that resveratrol and MitoQ treatment will improve antioxidant defenses and improve erectile function. In this study, we used a surgically castrated mouse model to induce ED. We treated mice with resveratrol or MitoQ for eight weeks. Following treatment, we sacrificed and harvested mice corpus cavernosum (CC). We measured the expression of genes related to antioxidant defenses by performing qRT‐PCR. Additionally, ex vivo vasoreactivity of the internal pudendal artery (IPA) and CC were assessed in response to concentration ranges of multiple agonists with DMT myograph system. One‐way ANOVA and Two‐way ANOVA, respectively, was used to compare differences between groups. Upon castration, vasorelaxation of the IPA and CC significantly declined. Antioxidant defenses were reduced with castration as seen by reduced expression in: Gclc, Gpx1, Prdx3, Prdx5, Nqo1, SOD2, SOD3, and Hmox1. After treatment, vasorelaxation did not improve however there were improvements in antioxidant gene expression. Resveratrol significantly increased expression of Gstm, CAT, SOD1. Additionally, MitoQ and resveratrol trended to increase several antioxidant genes. There was a partially restoration of Gpx1, Prdx3, Nqo1 and SOD2 levels and Hmox1 was restored back to sham levels. To conclude, neither long‐term administration of MitoQ nor resveratrol improved relaxation responses of the IPA or CC, however, they were able to stimulate and improve antioxidant gene expression. Even though these drugs were unable to improve erectile function on their own, they may be paired with other treatments such as PDE‐5 inhibitors, to ...

During spaceflight missions, astronauts are exposed to an extreme environment with high levels of radiation and microgravity, which negatively influence the cardiovascular system. With an increased development in space exploration and growing interest in manned missions to mars, it is of high importance to evaluate the health risks associated with long‐duration spaceflights. The increased risk of oxidative stress and inflammatory damage post‐spaceflight has been associated with cardiovascular dysfunction, but little is known about the influence of space exposure on erectile function, which is a critical component for quality of life in men. The purpose of this investigation was to determine the influence of long‐duration spaceflight on corpus cavernosum (CC) function. 86 adult male Sprague‐Dawley rats were randomized into 6 different groups with half of them enduring 4‐weeks of hindlimb unloading (HLU), and exposed to sham, 0.75Gy or 1.5Gy of simulated galactic cosmic radiation at the Ground‐based GCR Simulator at the NASA Space Radiation Laboratory (NSRL). Following a 6–9‐month recovery the rats were sacrificed, and CC tissue segments were harvested and mounted into a muscle strip myograph system for ex vivo functional assessment. CC reactivity to six 10‐s,30V‐electric field stimulations with progressive frequencies in the range of 1‐32 Hz targeting the non‐adrenergic non‐cholinergic (NANC) stimulation was assessed. The effects of HLU and radiation were determined by two‐way repeated measures ANOVA. High levels of radiation significantly decreased NANC‐mediated relaxation of the CC. Treatment with nitric oxide synthase (NOS) inhibitor L‐NAME completely inhibited tissue response to electric stimulation, showing that the relaxation was mainly driven by nitric oxide. Incubation of the CC tissue with the xanthine oxidase inhibitor allopurinol, the mitochondria‐targeted antioxidant mito‐TEMPO, and the superoxide dismutase (SOD) mimetic TEMPOL increased the relaxation response of the erectile tissue for the groups exposed to radiation, with little or opposite effect on the groups under no radiation exposure. Upon treatment with the Arginase inhibitor S‐(2‐boronoethyl)‐l‐cysteine (BEC), CC tissue for the groups under radiation exposure showed a significant improvement in relaxation under NANC electric field stimulation. Comparably, western blot analysis showed increased levels of oxidative stress and lipid peroxidation in the corpus cavernosum on the groups under radiation exposure by assessment of 4‐hydroxynonenal (HNE), as well as higher levels of arginase 1 and 2. This information suggests that increased oxidative stress from radiation exposure in long spaceflight trips impairs corpus cavernosum vasoreactivity and exposes new factors to consider with space exploration to ensure that astronauts can return to normal life after long trips in space.

Background: Emergency Contraception (EC) will help forestall unintended pregnancies, following an unprotected sexual intercourse or failure of regular family planning methods. EC knowledge is essential for every woman in the reproductive age group, especially single women who are unable to abstain from unprotected sex. Nevertheless, this knowledge and the utilization of this essential reproductive health product is poor among women across the globe. The female NYSC member of Nigeria stand a greater risk of unintended pregnancies, but little or no attention has been paid to this. Objectives:The present study is informed by the necessity to asses among female NYSC members' knowledge and utilization of EC and come out with information that may help the public and policy makers in fighting unintended pregnancies and its consequences in Nigeria.Methods: 181 self-structured, validated questionnaires were distributed among consenting female NYSC members systematically drawn from the 23 Local Government Areas of Sokoto State. SPSS version 20.0 statistical package was used to manage the database.Results: 22.8% of the respondents were found to have good knowledge of EC. Only 44.4% of this group believed it is morally alright to use EC. 39.5% of the respondents that confirmed being involved in an act that required EC ever used it. We also found that tribe/ ethnicity and geopolitical zones of respondents influenced their EC knowledge (χ 2 =8.505, p=0.037 and χ 2 =17.839, p=0.003, respectively). Conclusion:To address unintended pregnancies and the consequences among our young female graduates who stand a huge risk in this respect, formal sex education, advance provision of EC services and handy information strategies such as handbills on EC need be encouraged.