Exercise training improves the defective centrally mediated erectile responses in rats with type I diabetes

The Inflammation Network in the Pathogenesis of Erectile Dysfunction: Attractive Potential Therapeutic Targets

BACKGROUND

Erectile dysfunction (ED) is an evolving health problem in the aging male population. Chronic low-grade inflammation is a critical component of ED pathogenesis and a probable intermediate stage of endothelial dysfunction, especially in metabolic diseases, with the inclusion of obesity, metabolic syndrome, and diabetes.

OBJECTIVE

This review will present an overview of preclinical and clinical data regarding common inflammatory mechanisms involved in the pathogenesis of ED associated with metabolic diseases and the effect of antiinflammatory drugs on ED.

METHODS

A literature search of existing pre-clinical and clinical studies was performed on databases [Pubmed (MEDLINE), Scopus, and Embase] from January 2000 to October 2019.

RESULTS

Low-grade inflammation is a possible pathological role in endothelial dysfunction as a consequence of ED and other related metabolic diseases. Increased inflammation and endothelial/prothrombotic markers can be associated with the presence and degree of ED. Pharmacological therapy and modification of lifestyle and risk factors may have a significant role in the recovery of erectile response through reduction of inflammatory marker levels.

CONCLUSION

Inflammation is the least common denominator in the pathology of ED and metabolic disorders. The inflammatory process of ED includes a shift in the complex interactions of cytokines, chemokines, and adhesion molecules. These data have established that anti-inflammatory agents could be used as a therapeutic opportunity in the prevention and treatment of ED. Further research on inflammation-related mechanisms underlying ED and the effect of therapeutic strategies aimed at reducing inflammation is required for a better understanding of the pathogenesis and successful management of ED.

Effects of exercise on sexual function and central mechanism in the streptozotocin-induced diabetic rats

Diabetes mellitus is associated with the impairment of sexual function including desire and orgasmic dysfunction. Sexual dysfunction in the diabetes mellitus is due to a selective defect of the nitric oxide synthase (NOS) within paraventricular nucleus (PVN). c-Fos is an immediate early gene and c-Fos expression represents neuronal activity in response to various stimuli. In the present study, we investigated the effects of treadmill exercise on sexual behaviors and the expressions of NOS and c-Fos in the PVN were evaluated using streptozotocin (STZ)-induced diabetic rats. Diabetes mellitus was induced by intraperitoneal injection of STZ. The rats in the treadmill exercise groups were made to run on a treadmill for 30 min once a day during 4 weeks. Male sexual behaviors were evaluated by recording the number of mounting, intromission, and ejaculation frequency. The present results revealed that treadmill exercise ameliorated sexual dysfunction in the STZ-induced diabetic rats. Treadmill exercise restored the contents of NOS and c-Fos in the PVN. The improving effect of treadmill exercise on sexual function can be considered as the neuronal activating effect of exercise through increasing expressions of NO and c-Fos.

The Effect of microRNA-328 antagomir on erectile dysfunction in streptozotocin-induced diabetic rats

The study aimed at exploring the effect of microRNA-328 (miR-328) antagomir on erectile dysfunction (ED) in streptozotocin (STZ)-induced diabetic rats. A total of 120 male Sprague-Dawley (SD) rats were selected for this study. Fifteen rats were assigned as the diabetic control group and 75 out of the remaining rats (105 diabetic rat models) were divided into five groups with 15 rats in each group: diabetic ED, diabetic ED+negative control (NC), diabetic ED+miR-328 antagomir, diabetic ED+sildenafil and diabetic ED+miR-328 antagomir+sildenafil groups. The cGMP/AGEs production levels were measured using enzyme-linked immunosorbent assay (ELISA) test. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting were conducted for testing the expression level of miR-328, transcription and protein levels of endothelial nitric oxide synthase (eNOS) and dickkopf-3 (DKK3). The diabetic ED+miR-328 antagomir group had better erectile function, lower cGMP production level, transcription and protein levels of eNOS and DKK3 but higher AGEs production level than the diabetic control group. The diabetic control group showed higher cGMP production level transcription and protein levels of eNOS and DKK3 and lower production levels of AGEs and miR-328 than the diabetic ED and diabetic ED+NC groups. Our results indicated that miR-328 antagomir could improve ED in STZ-induced diabetic rats by regulating cGMP and AGEs.

Aerobic exercise training increases nitrergic innervation function and decreases sympathetic innervation function in mesenteric artery from rats fed a high-fat diet

INTRODUCTION

We investigated whether high-fat diet (HFD)-induced obesity was associated with modifications in mesenteric innervation function, the mechanisms involved, and the possible effects of aerobic exercise training on these changes.

MATERIALS AND METHODS

Male Wistar rats were divided into three groups: rats fed a standard diet (control group); rats fed a HFD (35% fat) for 8 weeks; and HFD rats submitted to aerobic exercise training (8 weeks, 5 times per week for 50  min). Segments of isolated mesenteric arteries were exposed to electric field stimulation (EFS) with or without phentolamine, suramin, or Nω nitro-L-arginine methyl ester. Noradrenaline, ATP, and nitric oxide release, and total and phosphorylated neuronal nitric oxide synthase (nNOS, P-nNOS) expression were also measured.

RESULTS

EFS contraction was greater in sedentary HFD than in control rats. Phentolamine reduced EFS contractions more markedly in HFD rats. Suramin decreased EFS contractions only in control rats. Phentolamine + suramin practically abolished EFS-induced contraction in control rats, whereas it did not modify it in the HFD rats. Noradrenaline release was greater and ATP was lower in HFD rats. Nω nitro-L-arginine methyl ester increased contractions to EFS only in segments from control rats. Nitric oxide release and nNOS and P-nNOS expressions were lower in arterial segments from HFD rats than from control rats. None of these changes in sedentary HFD rats was present in the trained HFD rats.

CONCLUSIONS

Enhanced sympathetic and diminished nitrergic components contributed to increased vasoconstrictor responses to EFS in sedentary HFD rats. All these changes were avoided by aerobic exercise training, suggesting that aerobic exercise could reduce peripheral vascular resistance in obesity.

Physical exercise associated with NO production: signaling pathways and significance in health and disease

Here we review available data on nitric oxide (NO)-mediated signaling in skeletal muscle during physical exercise. Nitric oxide modulates skeletal myocyte function, hormone regulation, and local microcirculation. Nitric oxide underlies the therapeutic effects of physical activity whereas the pharmacological modulators of NO-mediated signaling are the promising therapeutic agents in different diseases. Nitric oxide production increases in skeletal muscle in response to physical activity. This molecule can alter energy supply in skeletal muscle through hormonal modulation. Mitochondria in skeletal muscle tissue are highly abundant and play a pivotal role in metabolism. Considering NO a plausible regulator of mitochondrial biogenesis that directly affects cellular respiration, we discuss the mechanisms of NO-induced mitochondrial biogenesis in the skeletal muscle cells. We also review available data on myokines, the molecules that are expressed and released by the muscle fibers and exert autocrine, paracrine and/or endocrine effects. The article suggests the presence of putative interplay between NO-mediated signaling and myokines in skeletal muscle. Data demonstrate an important role of NO in various diseases and suggest that physical training may improve health of patients with diabetes, chronic heart failure, and even degenerative muscle diseases. We conclude that NO-associated signaling represents a promising target for the treatment of various diseases and for the achievement of better athletic performance.

Aerobic exercise training increases neuronal nitric oxide release and bioavailability and decreases noradrenaline release in mesenteric artery from spontaneously hypertensive rats

OBJECTIVE

To study the effect of aerobic exercise training on sympathetic, nitrergic and sensory innervation function in superior mesenteric artery from spontaneously hypertensive rats (SHRs).

METHODS

De-endothelized vascular rings from sedentary and trained SHRs (treadmill 12 weeks) were used. Vasomotor responses to electrical field stimulation (EFS), noradrenaline, nitric oxide donor DEA-NO and calcitonin gene-related peptide (CGRP) were studied. Neuronal nitric oxide synthase (nNOS) expression and nitric oxide, superoxide anions (O(2.-)), noradrenaline and CGRP levels were also determined.

RESULTS

Aerobic exercise training decreased vasoconstrictor response to EFS but increased noradrenaline response. Phentolamine decreased while N(ω)-nitro-(L)-arginine methyl ester ((L)-NAME) increased the response to EFS; the effect of both drugs was greater in trained animals. Training also decreased noradrenaline release and O(2.-) production and increased nNOS expression, nitric oxide release and the vasodilator response to DEA-NO. The O(2.-) scavenger tempol increased DEA-NO-induced vasodilation only in sedentary rats. The EFS-induced contraction was increased to a similar extent in both experimental groups by preincubation with CGRP (8-37). CGRP release and vasodilator response were not modified by training.

CONCLUSION

Aerobic exercise training decreases contractile response to EFS in mesenteric artery from SHRs. This effect is the net result of decreased noradrenaline release, increased sensitivity to the vasoconstrictive effects of noradrenaline and increased neuronal nitric oxide release and bioavailability. These modifications might contribute to the beneficial effects of aerobic exercise training on blood pressure.

What do most erectile dysfunction guidelines have in common? No evidence-based discussion or recommendation of heart-healthy lifestyle changes and/or Panax ginseng

Sexual health or erectile dysfunction (ED) state of the art guidelines provide a thorough overview of conventional prescription or other notable extrinsic treatment options. Yet, over the past 10-15 years, a plethora of international researchers have established that individual and comprehensive lifestyle changes can prevent and potentially improve ED. We review the lifestyle evidence that should equate to grade A or level 1 evidence recommendations for ED. We also review the evidence for Panax ginseng, an over-the-counter (OTC) dietary supplement with a 35-year history of laboratory investigations, multiple positive randomized trials over approximately 15 years and several independent meta-analyses and systematic reviews. Perhaps it is time to at least discuss and even emphasize lifestyle and other non-conventional interventions in ED guidelines so that patients can explore a diversity of potentially synergistic choices with their physicians and can improve their quality and quantity of life. Ignoring the consistent, positive data on lifestyle modifications in ED guidelines, for example, is tantamount to ignoring diet and lifestyle changes to reduce the risk of or ameliorate cardiovascular diseases.

Influence of exercise training on ischemic brain injury in type 1 diabetic rats

While exercise training (ExT) appears to influence cerebrovascular function during type 1 diabetes (T1D), it is not clear whether this beneficial effect extends to protecting the brain from ischemia-induced brain injury. Thus our goal was to examine whether modest ExT could influence transient focal ischemia-induced brain injury along with nitric oxide synthase (NOS)-dependent dilation of cerebral (pial) arterioles during T1D. Sprague-Dawley rats were divided into four groups: nondiabetic sedentary, nondiabetic ExT, diabetic (streptozotocin; 50 mg/kg ip) sedentary, and diabetic ExT. In the first series of studies, we measured infarct volume in all groups of rats following right MCA occlusion for 2 h, followed by 24 h of reperfusion. In a second series of studies, a craniotomy was performed over the parietal cortex, and we measured responses of pial arterioles to an endothelial NOS (eNOS)-dependent, a neuronal NOS (nNOS)-dependent, and a NOS-independent agonist in all groups of rats. We found that sedentary diabetic rats had significantly larger total, cortical, and subcortical infarct volumes following ischemia-reperfusion than sedentary nondiabetic, nondiabetic ExT, and diabetic ExT rats. Infarct volumes were similar in sedentary nondiabetic, ExT nondiabetic, and ExT diabetic rats. In contrast, ExT did not alter infarct size in nondiabetic compared with sedentary nondiabetic rats. In addition, ExT diabetic rats had impaired eNOS- and nNOS-dependent, but not NOS-independent, vasodilation that was restored by ExT. Thus ExT of T1D rats lessened ischemic brain injury following middle cerebral artery occlusion and restored impaired eNOS- and nNOS-dependent vascular function. Since the incidence of ischemic stroke is increased during T1D, we suggest that our finding are significant in that modest ExT may be a viable preventative therapeutic approach to lessen ischemia-induced brain injury that may occur in T1D subjects.

Physically active men show better semen parameters and hormone values than sedentary men

Physical exercise promotes many health benefits. The present study was undertaken to assess possible semen and hormone differences among physically active (PA) subjects and sedentary subjects (SE). The analyzed qualitative sperm parameters were: volume, sperm count, motility, and morphology; where needed, additional testing was performed. The measured hormones were: follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone (T), cortisol (C), and the ratio between T and C (T/C). Maximum oxygen consumption was also assessed to check for differences in fitness level. Statistically significant differences were found for several semen parameters such as total progressive motility (PA: 60.94 ± 5.03; SE: 56.07 ± 4.55) and morphology (PA: 15.54 ± 1.38, SE: 14.40 ± 1.15). The seminological values observed were supported by differences in hormones, with FSH, LH, and T being higher in PA than in SE (5.68 ± 2.51 vs. 3.14 ± 1.84; 5.95 ± 1.11 vs. 5.08 ± 0.98; 7.68 ± 0.77 vs. 6.49 ± 0.80, respectively). Likewise, the T/C ratio, index of anabolic versus catabolic status, was also higher in PA (0.46 ± 0.11 vs. 0.32 ± 0.07), which further supports the possibility of an improved hormonal environment. The present study shows that there are differences in semen and hormone values of physically active subjects and sedentary subjects. Physically active subjects seem to have a more anabolic hormonal environment and a healthier semen production.

Exercise is associated with better erectile function in men under 40 as evaluated by the International Index of Erectile Function

INTRODUCTION

Studies have shown an association between erectile dysfunction and sedentary lifestyle in middle-aged men, with a direct correlation between increased physical activity and improved erectile function. Whether or not this relationship is present in young, healthy men has yet to be demonstrated.

AIM

The aim of this study was to assess the association between physical activity and erectile function in young, healthy men.

MAIN OUTCOME MEASURES

The primary end points for our study were: (i) differences in baseline scores of greater than one point per question for the International Index of Erectile Function (IIEF); (ii) differences in baseline scores of greater than one point per question for each domain of the IIEF; (iii) exercise energy expenditure; and (iv) predictors of dysfunction as seen on the IIEF.

METHODS

The participants were men between the ages of 18 and 40 years old at an academic urology practice. Patients self-administered the Paffenbarger Physical Activity Questionnaire and the IIEF. Patients were stratified by physical activity into two groups: a sedentary group (≤1,400 calories/week) and an active group (>1,400 calories/week). Men presenting for the primary reason of erectile dysfunction or Peyronie's disease were excluded.

RESULTS

Seventy-eight patients had complete information in this study: 27 patients (34.6%) in the sedentary group (≤1,400 kcal/week) and 51 patients (65.4%) in the active group (>1,400 kcal/week). Sedentary lifestyle was associated with increased dysfunction in the following domains of the IIEF: erectile function (44.4% vs. 21.6%, P = 0.04), orgasm function (44.4% vs. 17.7%, P = 0.01), intercourse satisfaction (59.3% vs. 35.3%, P = 0.04), and overall satisfaction (63.0% vs. 35.3%, P = 0.02). There was a trend toward more dysfunction in the sedentary group for total score on the IIEF (44.4% vs. 23.5%, P = 0.057), while sexual desire domain scores were similar in both groups (51.9% vs. 41.2%, P = 0.37).

CONCLUSIONS

We have demonstrated that increased physical activity is associated with better sexual function measured by a validated questionnaire in a young, healthy population. Further studies are needed on the long-term effects of exercise, or lack thereof, on erectile function as these men age.