Dihydrotestosterone (DHT) rapidly increase after maximal aerobic exercise in healthy males: the lowering effect of phosphodiesterase's type 5 inhibitors on DHT response to exercise-related stress

PURPOSE

Few data exist on dihydrotestosterone (DHT) adaptation to exercise-related stress. The aim of the study was to investigate on serum DHT and other androgens' responses to acute aerobic exercises, and to verify if a long-acting phosphodiesterase's type 5 inhibitors could influence these responses, as previously observed for salivary testosterone.

METHODS

In a double-blind cross over study, 12 healthy trained male volunteers were submitted to both an acute sub-maximal and maximal exercise tests on cycle ergometer, after randomly receiving a two days placebo or tadalafil administration (20 mg, Cialis^®, Ely-Lilly, Indianapolis, IN, USA). Blood sample collections were performed at different time points before and after exercise. Serum DHT, total testosterone (TT), dehydroepiandrosterone sulfate (DHEAS) and luteinizing hormone (LH), were assayed.

RESULTS

Serum DHT increase in placebo treatment immediately post maximal aerobic exercise and return to basal values at 60 min of recovery whereas tadalafil administration significantly reduced the DHT increase after exercise. The values of areas under curves showed the increase of TT after acute sub-maximal and maximal exercise and of DHEAS only after acute maximal aerobic exercise independently from treatment.

CONCLUSIONS

In addition to testosterone, also DHT plays an exercise-related adaptive role during high intensity aerobic exercise, but its rapid useful effects during exercise have to be determined. We hypothesized that the increased androgens secretion during exercise could be mainly related to steroidogenic enzymes modifications in peripheral tissues (i.e., muscles). Moreover, the blunting effect of tadalafil on DHT increase support a possible role of peripheral nitric oxide/GMPc related pathways in influencing physical-stress related DHT metabolism.

Exercise-induced GH secretion is related to puberty

PURPOSE

Exercise represents a physiological stimulus that initiates the coordinated responses of hypothalamic-pituitary axis and sympathetic nervous system. Aims of the study were: 1) to analyze the response of GH, cortisol and prolactin to acute exercise in healthy children with normal GH response to stimulation tests 2) to evaluate the reliability of physical exercise as a screening test for GH secretion.

METHODS

Forty-four children (mean age 9.35 ± 2.69 years, range 4-13.7) underwent standardized Bruce's test on treadmill. Twenty-nine children were pre-pubertal (nine females and 20 males) and 15 children were pubertal (ten females and five males).

RESULTS

Exercise elicited a peak secretion of all the analyzed hormones. GH showed the highest mean percentage increase (558%), followed by prolactin (178%) and cortisol (23%). In 19/44 children (43.2%), GH peak did not reach the cut-off level of 8 ng/ml, considered as the normal GH response to stimulation tests. Despite a wide inter-individual variability, both GH peak and GH increase from baseline were higher in pubertal children than in pre-pubertal ones (GH peak: 13.49 ± 10.28 ng/ml versus 6.6 ± 4.09 ng/ml-p < 0.001; GH increase: 12.02 ± 10.30 ng/ml versus 5.28 ± 3.97 ng/ml-p < 0.001). The impact of puberty on both GH peak and GH increase was independent of sex, age, BMI SDS and VO₂max. No differences related to sex or pubertal status were found in cortisol and prolactin responses.

CONCLUSION

Exercise-induced GH secretion should not be considered a valuable screening tool in the diagnostic work-up of GH deficiency, due to the wide inter-individual variability in GH response. As described for standard GH stimulation tests, puberty represents the key factor that enhances GH secretion in healthy children.

Vitamin D, sport and health: a still unresolved clinical issue

Vitamin D metabolites have a pleiotropic role in human physiology, both in static and dynamic conditions, and a lot of vitamin D-related biological effects could influence physical and sport performances in athletes. Probably due to different factors (e.g., drugs, doping, nutrition, ultraviolet B radiation exposure), in athletes a very high prevalence of vitamin D inadequacy (i.e., deficiency or insufficiency) has been observed. Vitamin D inadequacy in athletes could be associated with specific health risks and to alterations of functional capacities, potentially influencing the fine adjustment of physical performances during training and sport competitions. When risk factors for vitamin D inadequacy exist, a preventive vitamin D supplementation is indicated, and if a vitamin D inadequacy is diagnosed, its supplementation is recommended. Unfortunately, on these issues many concerns remain unresolved. Indeed, it is not clear if athletes should be classified as a special population at increased risk for vitamin D inadequacy; moreover, in comparison to the non-athletic population, it is still not clear if athletes should have different reference ranges and different optimal target levels for serum vitamin D, if they have additional health risks, and if they need different type of supplementations (doses) for prevention and/or replacement therapy. Moreover, in athletes also the abuse of vitamin D supplements for ergogenic purposes raise different ethical and safety concerns. In this review, the main physio-pathological, functional and clinical issues that relate vitamin D to the world of athletes are described.

Sulodexide counteracts endothelial dysfunction induced by metabolic or non-metabolic stresses through activation of the autophagic program

OBJECTIVE

Endothelial dysfunction (ED) predisposes to venous thrombosis (VT) and post-thrombotic syndrome (PTS), a long-term VT-related complication. Sulodexide (SDX) is a highly purified glycosaminoglycan with antithrombotic, pro-fibrinolytic and anti-inflammatory activity used in the treatment of chronic venous disease (CVD), including patients with PTS. SDX has recently obtained clinical evidence in the "extension therapy" after initial-standard anticoagulant treatment for the secondary prevention of recurrent deep vein thrombosis (DVT). Herein, we investigated how SDX counteracts ED.

MATERIALS AND METHODS

Human umbilical vein endothelial cells (HUVEC) were used. Metabolic and non metabolic-induced ED was induced by treating with methylglyoxal (MGO) or irradiation (IR), respectively. Bafilomycin A1 was used to inhibit autophagy. The production of reactive oxygen species (ROS), tetrazolium bromide (MTT) assay for cell viability, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay for cell apoptosis, Real-time PCR and Western blot analysis for gene and protein expression were used.

RESULTS

SDX protected HUVEC from MGO- or IR-induced apoptosis by counteracting the activation of the intrinsic and extrinsic caspase cascades. The cytoprotective effects of SDX resulted from a reduction in a) ROS production, b) neo-synthesis and release of pro-inflammatory cytokines (TNFα, IL1, IL6, IL8), c) DNA damage induced by MGO or IR. These effects were reduced when autophagy was inhibited.

CONCLUSIONS

Data herein collected indicate the ability of SDX to counteract ED induced by metabolic or non-metabolic stresses by involving the intracellular autophagy pathway. Our experience significantly increases the knowledge of the mechanisms of action of SDX against ED and supports the use of SDX in the treatment of CVD, PTS and in the secondary prevention of recurrent DVT.

The use of prohibited substances for therapeutic reasons in athletes affected by endocrine diseases and disorders: the therapeutic use exemption (TUE) in clinical endocrinology

To protect sporting ethics and athletes' health, the World Anti-Doping Agency (WADA) produced the World Anti-Doping Code and The Prohibited List of substances and methods forbidden in sports. In accordance with the International Standards for Therapeutic Use Exemption (ISTUE), to avoid rule violations and sanctions, athletes affected by different endocrine diseases and disorders (e.g., adrenal insufficiency, diabetes, male hypogonadisms, pituitary deficit, thyroid diseases, etc.) who need to use a prohibited substance for therapeutic reasons (e.g., medical treatments, surgical procedures, clinical diagnostic investigations) must apply to their respective Anti-Doping Organizations (ADOs) to obtain a Therapeutic Use Exemption (TUE), if specific criteria are respected. The physicians who treat these athletes (i.e., endocrinologists, andrologists and diabetologists) are highly involved in these procedures and should be aware of their specific role and responsibility in applying for a TUE, and in adequately monitoring unhealthy athletes treated with prohibited substances. In this paper, the prohibited substances commonly used for therapeutic reasons in endocrine diseases and disorders (e.g., corticotropins, beta-blockers, glucocorticoids, hCG, insulin, GnRH, rhGH, testosterone, etc.), the role of physicians in the TUE application process and the general criteria used by ADO-Therapeutic Use Exemption Committees (TUECs) for granting a TUE are described.

Comparative study of testosterone and vitamin D analogue, elocalcitol, on insulin-controlled signal transduction pathway regulation in human skeletal muscle cells

PURPOSE

Skeletal muscle (Skm) plays a key role in regulating energetic metabolism through glucose homeostasis. Several hormones such as Testosterone (T) and Vitamin D (VD) have been shown to affect energy-dependent cell trafficking by determining Insulin (I)-like effects.

AIM

To elucidate possible hormone-related differences on muscular metabolic control, we analyzed and compared the effects of T and elocalcitol (elo), a VD analogue, on the activation of energy-dependent cell trafficking, metabolism-related-signal transduction pathways and transcription of gene downstream targets.

METHODS

Human fetal skeletal muscle cells (Hfsmc) treated with T or elo were analyzed for GLUT4 localization, phosphorylation/activation status of AKT, ERK1/2, IRS-1 signaling and c-MYC protein expression.

RESULTS

T, similar to elo, induced GLUT4 protein translocation likely in lipid raft microdomains. While both T and elo induced a rapid IRS-1 phosphorylation, the following dynamic in phosphorylation/activation of AKT and ERK1/2 signaling was different. Moreover, T but not elo increased c-MYC protein expression.

CONCLUSIONS

All together, our evidence indicates that whether both T and elo are able to affect upstream I-like pathway, they differently determine downstream effects in I-dependent cascade, suggesting diverse physiological roles in mediating I-like response in human skeletal muscle.

The phosphodiesterase 5 inhibitor sildenafil decreases the proinflammatory chemokine IL-8 in diabetic cardiomyopathy: in vivo and in vitro evidence

PURPOSE

Interleukin (IL)-8 is a proinflammatory C-X-C chemokine involved in inflammation underling cardiac diseases, primary or in comorbid condition, such diabetic cardiomyopathy (DCM). The phosphodiesterase type 5 inhibitor sildenafil can ameliorate cardiac conditions by counteracting inflammation. The study aim is to evaluate the effect of sildenafil on serum IL-8 in DCM subjects vs. placebo, and on IL-8 release in human endothelial cells (Hfaec) and peripheral blood mononuclear cells (PBMC) under inflammatory stimuli.

METHODS

IL-8 was quantified: in sera of (30) DCM subjects before (baseline) and after sildenafil (100 mg/day, 3-months) vs. (16) placebo and (15) healthy subjects, by multiplatform array; in supernatants from inflammation-challenged cells after sildenafil (1 µM), by ELISA.

RESULTS

Baseline IL-8 was higher in DCM vs. healthy subjects (149.14 ± 46.89 vs. 16.17 ± 5.38 pg/ml, p < 0.01). Sildenafil, not placebo, significantly reduced serum IL-8 (23.7 ± 5.9 pg/ml, p < 0.05 vs. baseline). Receiver operating characteristic (ROC) curve for IL-8 was 0.945 (95% confidence interval of 0.772 to 1.0, p < 0.01), showing good capacity of discriminating the response in terms of drug-induced IL-8 decrease (sensitivity of 0.93, specificity of 0.90). Sildenafil significantly decreased IL-8 protein release by inflammation-induced Hfaec and PBMC and downregulated IL-8 mRNA in PBMC, without affecting cell number or PDE5 expression.

CONCLUSION

Sildenafil might be suggested as potential novel pharmacological tool to control DCM progression through IL-8 targeting at systemic and cellular level.

Testosterone-mediated activation of androgenic signalling sustains in vitro the transformed and radioresistant phenotype of rhabdomyosarcoma cell lines

PURPOSE

Rhabdomyosarcoma (RMS), the most common soft-tissue sarcoma in childhood, rarely affects adults, preferring male. RMS expresses the receptor for androgen (AR) and responds to androgen; however, the molecular action of androgens on RMS is unknown.

METHODS

Herein, testosterone (T) effects were tested in embryonal (ERMS) and alveolar (ARMS) RMS cell lines, by performing luciferase reporter assay, RT-PCR, and western blotting experiments. RNA interference experiments or bicalutamide treatment was performed to assess the specific role of AR. Radiation treatment was delivered to characterise the effects of T treatment on RMS intrinsic radioresistance.

RESULTS

Our study showed that RMS cells respond to sub-physiological levels of T stimulation, finally promoting AR-dependent genomic and non-genomic effects, such as the transcriptional regulation of several oncogenes, the phosphorylation-mediated post-transductional modifications of AR and the activation of ERK, p38 and AKT signal transduction pathway mediators that, by physically complexing or not with AR, participate in regulating its transcriptional activity and the expression of T-targeted genes. T chronic daily treatment, performed as for the hormone circadian rhythm, did not significantly affect RMS cell growth, but improved RMS clonogenic and radioresistant potential and increased AR mRNA both in ERMS and ARMS. AR protein accumulation was evident in ERMS, this further developing an intrinsic T-independent AR activity.

CONCLUSIONS

Our results suggest that androgens sustain and improve RMS transformed and radioresistant phenotype, and therefore, their therapeutic application should be avoided in RMS post puberal patients.

The phosphodiesterase 5 inhibitor tadalafil regulates lipidic homeostasis in human skeletal muscle cell metabolism

PURPOSE

Tadalafil seems to ameliorate insulin resistance and glucose homeostasis in humans. We have previously reported that tadalafil targets human skeletal muscle cells with an insulin (I)-like effect. We aim to evaluate in human fetal skeletal muscle cells after tadalafil or I: (i) expression profile of I-regulated genes dedicated to cellular energy control, glycolitic activity or microtubule formation/vesicle transport, as GLUT4, PPARγ, HK2, IRS-1, KIF1C, and KIFAP3; (ii) GLUT4, Flotillin-1, and Caveolin-1 localization, all proteins involved in energy-dependent cell trafficking; (iii) activation of I-targeted paths, as IRS-1, PKB/AKT, mTOR, P70/S6K. Free fatty acids intracellular level was measured. Sildenafil or a cGMP synthetic analog were used for comparison; PDE5 and PDE11 gene expression was evaluated in human fetal skeletal muscle cells.

METHODS

RTq-PCR, PCR, western blot, free fatty acid assay commercial kit, and lipid stain non-fluorescent assay were used.

RESULTS

Tadalafil upregulated I-targeted investigated genes with the same temporal pattern as I (GLUT4, PPARγ, and IRS-1 at 3 h; HK2, KIF1C, KIFAP3 at 12 h), re-localized GLUT4 in cell sites positively immune-decorated for Caveolin-1 and Flotillin-1, suggesting the involvement of lipid rafts, induced specific residue phosphorylation of IRS-1/AKT/mTOR complex in association with free fatty acid de novo synthesis. Sildenafil or GMP analog did not affect GLUT4 trafficking or free fatty acid levels.

CONCLUSION

In human fetal skeletal muscle cells tadalafil likely favors energy storage by modulating lipid homeostasis via IRS-1-mediated mechanisms, involving activation of I-targeted genes and intracellular cascade related to metabolic control. Those data provide some biomolecular evidences explaining, in part, tadalafil-induced favorable control of human metabolism shown by clinical studies.

Testosterone insulin-like effects: an in vitro study on the short-term metabolic effects of testosterone in human skeletal muscle cells

PURPOSE

Testosterone by promoting different metabolic pathways contributes to short-term homeostasis of skeletal muscle, the largest insulin-sensitive tissue and the primary site for insulin-stimulated glucose utilization. Despite evidences indicate a close relationship between testosterone and glucose metabolism, the molecular mechanisms responsible for a possible testosterone-mediated insulin-like effects on skeletal muscle are still unknown.

METHODS

Here we used undifferentiated proliferating or differentiated human fetal skeletal muscle cells (Hfsmc) to investigate the short-term effects of testosterone on the insulin-mediated biomolecular metabolic machinery. GLUT4 cell expression, localization and the phosphorylation/activation of AKT, ERK, mTOR and GSK3β insulin-related pathways at different time points after treatment with testosterone were analyzed.

RESULTS

Independently from cells differentiation status, testosterone, with an insulin-like effect, induced Glut4-mRNA expression, GLUT4 protein translocation to the cytoplasmic membrane, while no effect was observed on GLUT4 protein expression levels. Furthermore, testosterone treatment modulated the insulin-dependent signal transduction pathways inducing a rapid and persistent activation of AKT, ERK and mTOR, and a transient inhibition of GSK3β. T-related effects were shown to be androgen receptor dependent.

CONCLUSION

All together our data indicate that testosterone through the activation of non-genomic pathways, participates in skeletal muscle glucose metabolism by inducing insulin-related effects.

Sport and male sexuality

The relationships between sport and sexuality in males are of great social and clinical interest, because of sports and motor activities that highly promote social and sexual relationships. Even if few literature exist, two main questions should be taken into account: whether and how physical exercise and sport positively or negatively influence sexual health and behavior and/or whether and how sexual behavior may affect a sub-sequent sport performance. Physical exercise and sport per se can influence, positively or negatively, the hypothalamic-pituitary-testicular axis function and, consequently, the individual's reproductive and/or sexual health. This depends on individual factors such as genetic and epigenetic ones and on different variables involved in the practice of sport activities (type of sport, intensity and duration of training, doping and drug use and abuse, nutrition, supplements, psychological stress, allostatic load, etc.). If well conducted, motor and sport activities could have beneficial effects on sexual health in males. Among different lifestyle changes, influencing sexual health, regular physical activity is fundamental to antagonize the onset of erectile dysfunction (ED). However, competitive sport can lead both reproductive and/or sexual tract damages and dysfunctions, transient (genital pain, hypoesthesia of the genitalia, hypogonadism, DE, altered sexual drive, etc.) or permanent (hypogonadism, DE, etc.), by acting directly (traumas of the external genitalia, saddle-related disorders in cyclists, etc.) or indirectly (exercise-related hypogonadism, drug abuse, doping, stress, etc.). Sexual activities shortly performed before a sport competition could differently influence sport performance. Due to the few existing data, it is advisable to avoid an absolute pre-competition sexual abstinence.

Assessment of pN-GAL as a marker of renal function in elite cyclists during professional competitions

Glomerular filtration rate (GFR) has been shown to be lower than physiological values during exercise with a strong negative correlation with exercise intensity. Among new markers of renal function, neutrophil gelatinase-associated lipocalin (NGAL) seems to be very promising. It is an early, sensitive and specific marker of acute kidney injury (AKI) with two isoforms: plasma NGAL (pNGAL) and urinary NGAL (uNGAL). The aim of the present study was to assess acute variations in NGAL plasma levels after performing high endurance physical exercise in a group of professional cyclists during the two major European professional cycling competitions (Giro D’Italia and Tour de France). Eighteen professional cyclistis were recruited for the study. A blood sample was collected during rest (after 8 hours fasting) and immediately after the competition (mountain stages) in order to assess the effect of very intense exercise on kidney function by measuring the variations of pNGAL. We also assessed plasma levels of creatinine, creatine-kinase (CK), LDH, transaminases and electrolytes. The results showed that Creatinine, CK and electrolytes levels remained almost stable between rest and post-competition. The levels of transaminases and NGAL showed a mild increase between rest and post-competition, with a significant difference between the two values only for transaminases (p=0.005). However, post-competition values of all investigated variables remained within the physiological range. The results of the present study suggest that even if NGAL values mildly rose after competition, no kidney injury occurred in these highly trained athletes during mountain stages of professional competitions. Other studies in literature confirmed that high endurance physical exercise seems not to cause renal injury in elite athletes. This is probably due to adaptive mechanisms of renal function and to the adaptation to physical stress gained with training.

Short-term, supra-physiological rhGH administration induces transient DNA damage in peripheral lymphocytes of healthy women

PURPOSE

While a good safety for recombinant human growth hormone (rhGH) therapy at replacement doses is recognized, a possible link between high concentration of the GH-IGF-I axis hormones and side negative effect has been reported. The aim of this pilot study was to assess whether a short-term exposure to supra-physiological doses of rhGH may affect DNA integrity in human lymphocytes (PBL).

METHODS

Eighteen healthy Caucasian female (24.2 ± 3.5 years) were randomly included in a Control (n = 9) and rhGH administration group (n = 9, 3-week treatment). DNA damage (comet assay), chromosomal breaks, and mitotic index in phytohemagglutinin-stimulated PBL were evaluated before (PRE), immediately (POST), and 30 days (POST30) after the last rhGH administration (0.029 mg kg^- 1 BW; 6 days/week), together with serum IGF-1 and IGFBP-3 concentrations.

RESULTS

rhGH administration increased IGF-I, without evidence of persisting IGF-I and IGFBP-3 changes 30 days after withdrawal. Total DNA breakage (% DNA in tails) was not significantly different in subjects treated with rhGH in comparison with controls, although the rhGH-treated subjects showed an higher percentage of heavily damaged nuclei immediately after the treatment (POST30 vs. PRE: p = 0.003), with a lower mitogenic potential of lymphocytes, detectable up to the POST30 (PRE vs. POST: p = 0.02; PRE vs. POST30: p = 0.007).

CONCLUSIONS

This pilot study showed that 3 weeks of short-term supra-physiological rhGH administration in healthy women induce a transient DNA damage and mitogenic impairment in PBL. The analysis of DNA damage should be explored as useful tool in monitoring the mid to long-term effects of high rhGH treatment or abuse.

Supra-physiological rhGH administration induces gender-related differences in the hypothalamus-pituitary-thyroid (HPT) axis in healthy individuals

PURPOSE

The use of recombinant human growth hormone (rhGH) is a common habit among athletes. While the effects of rhGH administration have been described with contrasting results in males, no data exist in females to date. The aim of the present study was to evaluate the effects of rhGH administration on TSH, FT₄ and FT₃ levels and the time requested to return to baseline values after treatment withdrawal.

METHODS

Twenty-one healthy trained male and female athletes were treated with 0.03 mg rhGH/kg body mass 6 days/week for 3 weeks. We collected blood samples immediately before the first daily rhGH administration, at 3, 4, 8, 15 and 21 days of treatment and at 3 and 9 days after rhGH withdrawal.

RESULTS

In males, rhGH administration induced a significant (p < 0.01) early and stable TSH decrease and IGF-I increase, and a delayed FT₄ reduction without FT₃ modification, suggesting a central regulatory mechanism. In females, rhGH administration induced a significant (p < 0.01) early and transient TSH decrease and IGF-I increase, and a transient reduction in FT₄ without any changes in FT₃ concentrations. rhGH withdrawal was associated with a prompt normalization of TSH and FT₄ levels in males, while in females the effects of rhGH treatment had already disappeared during the last period of treatment.

CONCLUSION

We suggest that rhGH inhibits TSH at central level both in males and females. The pattern of normalization was different in the two genders probably due to gonadal steroids modulation on GH-IGF-I axis.

Acute endothelial response to testosterone gel administration in men with severe hypogonadism and its relationship to androgen receptor polymorphism: a pilot study

PURPOSE

Testosterone (T) exerts different effects on the cardiovascular system. Despite this knowledge, the acute vascular effect of androgen remains still poorly understood.

METHODS

We investigated the acute effects of T on vascular function in ten men (18-40 years age) with hypogonadism and severe hypotestosteronemia [serum total testosterone (TT) = 0.6 ± 0.3 ng/mL]. In a 4-day double-blind, randomized, placebo-controlled crossover study, we administered 80 mg daily dose of transdermal-T gel (TG) and evaluated endothelial variations with Endopat2000 (reactive hyperemia index, RHI and the augmentation index, AI); also, CAG repeat polymorphism in exon 1 of the androgen receptor gene was investigated.

RESULTS

After TG administration, RHI significantly improved at 4 h (p < 0.05), while AI improvement was recorded at 4 and 96 h, also when adjusted for heart rate (AI@75; p < 0.01 and p < 0.001, respectively). Direct relationships between ΔT, ΔDHT and ΔRHI variations (r = 0.37, p < 0.01; r = 0.17, p < 0.05, respectively) as well as between "CAG repeats" length and ΔLnRHI at 96 h (p < 0.03, r (2) = 0.47) were found. An inverse relationship between ΔT and ΔAI (p < 0.01, r = -0.35) and ΔAI@75 (p < 0.01, r = -0.38) were found.

CONCLUSION

Administration of TG causes an acute vasodilation and improves arterial stiffness probably due to non-genomic actions of T. Endothelial vasodilatory response was more pronounced depending on higher plasma TT and DHT levels attained. Clinical implications in elderly frail populations are discussed.

Phosphodiesterase type 5 inhibitors: back and forward from cardiac indications

PDE5 inhibitors (PDE5i) are widely known as treatment for erectile dysfunction (ED). This favorable action has emerged as a "side effect" from pioneering studies when PDE5i have been originally proposed as treatment for coronary artery disease (CAD). PDE5i showed marginal benefits for CAD treatment; although disappointing for that indication, they improved systemic and pulmonary vasodilation and ameliorated general endothelial function. Therefore, PDE5i have been approved and licensed also for pulmonary artery hypertension (PAH), besides ED. Nowadays, fine-tuned biomolecular mechanisms of PDE5i are well recognized to be beneficial onto myocardial contractility and geometry, to reduce tissue fibrosis, hypertrophy and apoptosis. PDE5i consistently exert benefits on heart failure, infarct, cardiomyopathy. The concept that PDE5i likely blunt Th1-driven inflammatory processes, which shift the homeostatic balance from health to disease, has emerged; PDE5i seem to decrease the release of active biomolecules from cells to tissues interested by inflammation. In this view, following clinical and basic research progresses, PDE5i can be undoubtedly "re-allocated" for cardiac indications and, hopefully, they could be approved as therapeutic tools to treat and prevent heart disease. This review aims to summarize PDE5i different clinical applications, from past to present and future, focusing on their potential power as treatment for cardiac diseases.

The endocrine disruptor cadmium alters human osteoblast-like Saos-2 cells homeostasis in vitro by alteration of Wnt/β-catenin pathway and activation of caspases

PURPOSE

The pollutant Cadmium (Cd) is widespread in the environment and causes alterations of human health by acting as an endocrine disruptor. Bone tissue seems to be a crucial target of Cd contamination. Indeed, we have previously demonstrated that this endocrine disruptor induces osteoblast apoptosis and necrosis. Thus, aim of this study was to further evaluate the effect of Cd on osteoblasts homeostasis, investigating potential modification of the Wnt/β-catenin intracellular pathway, the intracellular process involved in programmed cellular death and the cytoskeletal alterations.

MATERIAL AND METHODS

To this purpose, human osteoblastic Saos-2 cells, a human osteosarcoma osteoblast-like cell line, were cultured and treated with Cd.

RESULTS

Osteoblastic cells were treated for 6 h with 10μM Cd, which induced nuclear translocation of β-catenin and increased expression of Wnt/β-catenin target genes. Longer exposure to the same Cd concentration induced osteoblastic cell apoptosis. To better characterize the intracellular events involved in these Cd-induced alterations, we evaluated the effect of Cd exposure on actin filaments and proteins associated to cytoskeletal actin, characterized by the presence of LIM domains. Long (15, 24 h) exposure of osteoblasts to Cd reduced LIM proteins expression and induced actin filaments destruction and a significant caspase-3 activation after 24 h. In addition, to prove that Cd induces osteoblastic cells apoptosis after long exposure, we performed TUNEL assay which demonstrated increase of cell apoptosis after 24 h.

CONCLUSION

In conclusion, our study shows that osteoblasts exposed to Cd for short intervals of time demonstrated an increase in cell proliferation through a Wnt/β-catenin dependent mechanism, likely as a compensatory mechanism in response to cell injury. Longer exposure to the same Cd concentration induced cells apoptosis through cytoskeleton disruption-mediated mechanisms and caspase activation.

The environmental pollutant cadmium induces homeostasis alteration in muscle cells in vitro

BACKGROUND

Cadmium (Cd) is a heavy metal widely distributed throughout the environment as a result of contamination from a variety of sources. It exerts toxic effects in many tissues but scarce data are present as yet on potential effects on skeletal muscle tissue.

AIM

To evaluate the potential alteration induced by Cd in skeletal muscle cells.

MATERIALS AND METHODS

C2C12 skeletal muscle cells were treated with Cd at different times of cellular differentiation and gene expression was evaluated.

RESULTS

Exposure to Cd decreased significantly p21 mRNA expression and strongly up-regulated cyclin D1 mRNA expression in committed cells and in differentiated myotubes. Moreover, myogenin, fast MyHC-IIb and slow MyHC-I mRNAs expression were also significantly decreased both in committed cells and in myotubes. Moreover, Cd exposure induced a strong increase of Pax3, Pax7 and Myf5 mRNAs expression and stimulated an up-regulation of IL6 and TNF-α proinflammatory cytokines.

CONCLUSION

These data lead to hypothesize that environmental Cd exposure might trigger an injury-like event in muscle tissue, possibly by an estrogen receptor-mediated mechanism.

Testosterone responses to standardized short-term sub-maximal and maximal endurance exercises: issues on the dynamic adaptive role of the hypothalamic-pituitary-testicular axis

BACKGROUND

Few and conflicting data on the acute adaptive role of the hypothalamic-pituitary-testicular (HPT) axis to sub-maximal endurance exercise exist.

AIMS

To investigate the acute HPT axis responses to standardized endurance exercises in a laboratory setting and the correlations between testosterone and classic adaptive hormones variations.

SUBJECTS AND METHODS

12 healthy male volunteers were recruited for this experimental study. Serum PRL, GH, ACTH, LH, cortisol, DHEAS, testosterone [total (TT), calculated free (cFT) and bioavailable (cBioT)], SHBG, and respective ratios, were evaluated before and after a 30-min sub-maximal exercise on cycle ergometer at individual anaerobic threshold (IAT) and a maximal exercise until exhaustion. Blood samples were collected before exercise (30, 15 min and immediately before), immediately after and at different time points during recovery (+15, +30 and +60 min) for hormones assays. Oxygen consumption and lactate concentration were evaluated.

RESULTS

Testosterone (TT, cFT and cBioT) acutely increased in all volunteers after both exercises. Testosterone increased in parallel to GH after both exercises and to cortisol only after maximal exercise. Differently from other increased hormones, testosterone increases were not correlated to exercise-intensity-related variables. The anabolic/catabolic steroids ratios were higher after sub-maximal exercise, compared to maximal.

CONCLUSIONS

A 30-min sub-maximal endurance exercise acutely increased serum testosterone similarly to maximal exercise, but without cortisol increases. Exercise-related testosterone peaks should be considered adaptive phenomena, but few data on their short- and long-term effects exist. Investigations on the mechanisms of adaptation to exercise in active individuals with physiological or pathological hypo-testosteronemia are warranted.

Insulin-like effect of the phosphodiesterase type 5 inhibitor tadalafil onto male human skeletal muscle cells

BACKGROUND

Phosphodiesterase type 5 inhibitors (PDE5i), widely used to treat male erectile dysfunction, seem to counteract insulin resistance (IR) in animals and humans. IR, primarily manifest in peripheral tissues and particularly in skeletal muscle, is due to impaired insulin signal transduction. Investigators have been focusing onto intracellular defects responsible for IR to identify suitable pharmacological tools targeted toward the specific defects. Albeit some effects of PDE5i have been reported onto animal muscular tissues or cells, whether and how they might affect metabolic processes directly in human skeletal muscle still remains unclear.

AIM

We aimed to investigate in human fetal skeletal muscle cells (Hfsmc) the effect of tadalafil, one of PDE5i, onto some intracellular factors involved in response to insulin, such as ras-raf mitogen activated protein kinase (MAPK), phosphatidylinositol 3-kinase/protein kinase B (PKB/Akt), glycogen synthase kinase 3β (GSK-3β), and the transcriptional factor c-Myc; proliferation rate; lactate (lact) and free fatty acid (ffa) release; activity of citrate synthase (CS) and succinate dehydrogenase (SDH), both enzymes of Kreb's cycle; PDE5 gene expression.

MATERIALS AND METHODS

Western blot analysis, enzyme-linked immunosorbent assay, enzymatic assays, cell count, MTT assay and Real Time PCR were performed in Hfsmc with and without tadalafil.

RESULTS

In Hfsmc tadalafil affected the insulin-related intracellular cascade, by increasing MAPK, PKB/Akt, GSK-3β phosphorylation and c-Myc expression. ffa release and CS activity also significantly increased, with no changes in SDH activity and lact release.

CONCLUSIONS

Tadalafil, like insulin, targeted part of the machinery dedicated to energy management and metabolic control in human skeletal muscle cells.

Impact of different concentrations of human recombinant growth hormone on T lymphocytes

The aim of the present study is to evaluate the effects induced by increasing concentrations of human recombinant growth hormone on T lymphocytes. Ten healthy volunteers and twelve subjects with symptomatic allergies were enrolled in the study. Peripheral blood mononuclear cells and purified T lymphocytes were cultured in the presence of graded concentrations of growth hormone. Following appropriate in vitro stimulations, the proportion of apoptotic T cells, the percentage of activated T lymphocyte subpopulations, the phytohemagglutinin responsiveness and the Th2 response were assessed by flow cytometry analysis. Moreover, in order to evaluate the phosphoinositol-3-kinase signaling pathway involvement, cells were also analyzed after treatment with LY294002. The treatment with different concentrations of growth hormone did not influence the activation pattern of un-stimulated T lymphocytes. On the contrary, growth hormone was able to modify the CD38/HLA-DR co-expression of T cells activated with phytohemoagglutinin. A different response was observed when samples obtained from healthy donors and from subjects with symptomatic allergies were analysed. Moreover, growth hormone treatment was able to increase the Th2 response in the samples obtained from healthy donors only. The results of the present study strongly support the hypothesis that growth hormone administration may play an important role in conditions of impaired/activated immune systems. The observation that growth hormone administration at high doses may reverse its effects and that it may promote a Th2-oriented response have significant clinical implications when considering the use of this hormone for artificially enhancing the physical performances of healthy athletes.

Why glucocorticosteroids should remain in the list of prohibited substances: a sports medicine viewpoint

In addition to their therapeutic applications, glucocorticosteroids have been widely used and abused in the belief that these substances may enhance athletic performance. Analysis of athlete urine samples by antidoping laboratories around the world support this conclusion. It is commonly accepted in medical practice to use local glucocorticosteroid injections in the treatment of non-infectious local musculotendinous inflammatory conditions conveying symptom relief and often a speedier return to sporting activity. This practice is not to be considered illicit, but sports physicians must accept that such an intervention is not in itself an immediate cure and that an athlete will still require a period of recuperation before continuing sporting activity. How long such a period of recuperation should last is a matter of conjecture and there is little concrete data to support what is, or what is not, an acceptable period of inactivity. In the interest of athlete safety, we would propose to maintain systemic glucocorticosteroids on the World Anti-Doping Agency&apos;s (WADA) list of prohibited substances, both in and out-of-competition as well as a mandatory period of 48 hours of rest from play after receiving a local glucocorticosteroid injection.

Subclinical hyperthyroidism and sport eligibility: an exploratory study on cardiovascular pre-participation screening in subjects treated with levothyroxine for multinodular goiter

BACKGROUND

Subclinical hyperthyroidism (sHT) affects cardiovascular (CV) morphology and function; whether such changes can impact on sport eligibility is unclear.

AIM

This exploratory study evaluated the CV system and sport eligibility in athletes with levothyroxine-induced sHT, in the setting of mandatory pre-participation screening.

SUBJECTS AND METHODS

A full, non-invasive CV screening (history and physical examination, 12-lead ECG, echocardiography, 24-hour Holter ECG, exercise stress test) was performed in two groups of untrained female athletes affected by non-toxic multinodular goiter. One group was taking levothyroxine at mildly suppressive doses (TG) whereas the other was untreated (UG). There was also a group of healthy controls (HC).

RESULTS

In TG the following characteristics were observed: a) a higher resting heart rate (HR; p<0.01 and p<0.05, vs HC and UG respectively), b) a thicker left ventricular posterior wall (p<0.05 vs HC, and p<0.05 vs HC and UG, respectively), c) a higher mean HR during the 24-hour Holter ECG (p<0.01 and p<0.05, vs HC and UG respectively), and d) a lower achieved maximum work load (p<0.05, vs HC). No differences in the prevalence of cardiac arrhythmias among groups were observed. Sport eligibility was granted to all except one subject in the TG.

CONCLUSIONS

Although some alterations were found in athletes with levothyroxine-induced mild sHT, these are probably of limited clinical relevance and they did not contraindicate sport participation in the majority of cases. Future research to address both health risks and the need for specific evaluations (e.g. free thyroxine, TSH, echocardiography) during the preparticipation screening of athletes with sHT is warranted.

Urinary and serum hormones profiles after testosterone enanthate administration in male hypogonadism: concerns on the detection of doping with testosterone in treated hypogonadal athletes

OBJECTIVE

To describe serum and urinary hormones, androgens metabolites and testosterone/epitestosterone ratio profiles after testosterone administration in male hypogonadal volunteers, and to evaluate their possible usefulness in detecting doping with testosterone in treated hypogonadal athletes.

DESIGN

Controlled open label design vs placebo; pharmacokinetic study.

PARTICIPANTS

Ten male volunteers affected by severe hypogonadism (serum testosterone <2.31 ng/ml).

INTERVENTIONS AND MAIN OUTCOME MEASURES

Serum and urinary parameters were evaluated, by radioimmunoassay and gas chromatography-mass spectrometry, before and at different time points for 7/3 weeks after a single administration of testosterone enanthate (250 mg) or placebo, respectively.

RESULTS

As partially known, testosterone administration increased, with great individual variability, urinary concentrations of glucuronide testosterone, androsterone, etiocholanolone, 5alpha-androstane- 3alpha,17beta-diol, 5beta-androstane-3alpha,17beta-diol, testosterone/ epitestosterone and testosterone/LH ratios; and decreased epitestosterone and 5alpha-androstane-3beta,17beta-diol/5beta-androstane- 3alpha,17beta-diol ratio. Serum testosterone and dihydrotestosterone increased in all volunteers, and concentrations higher than the upper reference limits were observed in many volunteers until 2 weeks after testosterone administration.

CONCLUSION

Whereas the observed prolonged hyperandrogenism partially limited data interpretation, the report ed characteristics of variation of urinary parameters might be used to suspect testosterone misuse in hypogonadal athletes treated with testosterone enanthate. In this sense, while the actual threshold for tes tos terone/epites tos ter one ratio was confirmed to be of reduced usefulness, we suggest a contemporary evaluation of whole urinary androgen metabolites profile and serum androgens, at specific time points after testosterone enanthate administration. Moreover, an adequate tailoring of treatment, to avoid transitory hyperandrogenism, is highly advisable. Further studies on strategies for detecting doping with testosterone in hypogonadal athletes are warranted.

Is explosive performance influenced by androgen concentrations in young male soccer players?

OBJECTIVE

There is growing interest in the implementation and assessment of strength and conditioning programmes among young children. The purpose of this study was to examine the association between given anthropometric characteristics, pubertal development, salivary androgen hormones and explosive leg power in young soccer players.

METHODS

51 (age range 10-14 years) soccer players were investigated. The relations between age, pubertal developmental stages, testicular volume, weight, height, body fat, fat free mass, salivary DHEAS concentrations, salivary testosterone concentrations and lower limb explosive power were evaluated.

RESULTS

Standing long jump length was positively correlated (p<0.05) with age (11.7 (SD 1.2) years, r = 0.66), pubertal developmental stages (mode and range: 1 (1-4), r = 0.64), testicular volume (8.8 (5.2) ml, r = 0.58), height (1.50 (0.10) m, r = 0.34), weight (43.7 (9.1) kg, r = 0.34), fat free mass (35.4 (7.2) kg, r = 0.67), salivary DHEAS concentrations (4.4 (1.2) ng/ml, r = 0.38) and negatively correlated with body fat (18.6 (7.0) kg; r = -0.49, p<0.05). There was no significant correlation between salivary testosterone concentrations (0.3 (0.1) ng/ml, r = 0.12) and standing long jump.

CONCLUSIONS

Results of the present investigation demonstrated that age, pubertal developmental stages, testicular volume, weight, height, fat free mass, and salivary DHEAS concentrations were associated with standing long jump performance. In addition, salivary testosterone concentrations were not related to explosive leg power. Results of the present investigation suggest that the teacher/coach should evaluate long jump performance relative to the subject's given biological characteristics, and not simply established standards based on chronological age.

The Long-Acting Phosphodiesterase Inhibitor Tadalafil does not Influence Athletes' V·O2max, Aerobic, and Anaerobic Thresholds in Normoxia

Whereas experimental studies showed that in healthy trained subjects, the phosphodiesterase-5 inhibitor (PDE-5i) sildenafil improves exercise capacity in hypoxia and not in normoxia, no studies on the effects of the long half-life PDE-5i tadalafil exist. In order to evaluate whether tadalafil influences functional parameters and performance during a maximal exercise test in normoxia, we studied 14 healthy male athletes in a double-blind cross-over protocol. Each athlete performed two tests on a cycle ergometer, both after placebo or tadalafil (at therapeutic dose: 20 mg) administration. Oxygen consumption (VO2), blood lactate, respiratory exchange ratio, rate of perceived exertion, arterial blood pressure (BP), heart frequency (HR) and oxygen pulse (VO2/HR) were evaluated before exercise, at individual ventilatory and anaerobic thresholds (IVT and IAT), at VO2max and during recovery. Compared to placebo, a single tadalafil administration significantly reduced systolic BP before and after exercise (p < 0.05), decreased VO2/HR at IVT (13.3 +/- 1.8 vs. 14.5 +/- 2.1 mL . beat (-1); p = 0.03), but did not modify individual VO2max, IVT, or IAT. In healthy athletes, 20 mg of tadalafil does not substantially influence physical fitness-related parameters, exercise tolerance, and cardiopulmonary responses to maximal exercise in normoxia; it remains to be verified if higher doses/prolonged use influence health and/or sport performance in field conditions.

Effect of tadalafil on anaerobic performance indices in healthy athletes

OBJECTIVE

Given the therapeutic and non-therapeutic use of the tadalafil, (phosphodiesterase-5 inhibitor, PDE-5i), we examined its effects on anaerobic performance indices.

METHODS

In total, 12 well-trained subjects reported to the laboratory on two occasions 1 week apart to perform a 30 s Wingate anaerobic power test (WAnT) on a bicycle ergometer. The day before the WAnT, the subjects were double-blinded to receive an oral dose of tadalafil (20 mg) or placebo. Blood lactate value at rest and 1, 3, 6 and 10 minutes of recovery phase, mean power, peak power, time to peak power and fatigue index were assessed for each WAnT.

RESULTS

Blood lactate values at the 3-min recovery WAnT increased significantly in the tadalafil condition (mean (SD) 13.9 (1.7) v 12.8 (1.3) mmol/l; p<0.05) and time to peak power decreased significantly (6.3 (1.3) v 5.7 (1.5) s; p = 0.05). No differences were observed in any other parameters between the two conditions.

CONCLUSION

The primary finding of this investigation was that the administration of a single dose of a long-term PDE-5i does not substantially influence anaerobic performance indices. However, results demonstrated both an increase in lactate values at the 3-min point of the recovery phase and a decrease in time to peak power.

Do non-steroidal anti-inflammatory drugs influence the steroid hormone milieu in male athletes?

Prostaglandins modulate the hypothalamus-pituitary-adrenal and -gonadal axis pathways. We explored the effects of a single course of treatment with acetylsalicylic acid (ASA), an inhibitor of prostaglandin synthesis, on the steroid milieu in athletes. Morning plasma cortisol (F), dehydroepiandrosterone sulphate, free-testosterone, testosterone (T) and their ratios were evaluated before and after the administration of either ASA or placebo in twelve male athletes, when affected by minor musculoskeletal trauma and, as control, after a five/six week wash-out in healthy conditions respectively. One tablet of ASA (800 mg), or placebo, was administered two times daily for 10 days during treatment. All the volunteers suspended exercise training during treatment. The results revealed that compared to placebo, plasma F was significantly lower after ASA treatment (p = 0.023). Furthermore, the comparison of hormone's absolute and percentage of variations (Delta and Delta%) between ASA and placebo treatment showed significant differences respectively for DeltaF (p = 0.045), for DeltaT (p = 0.047), for DeltaT/F (p = 0.042), for DeltaF% (p = 0.04) and for DeltaT% (p = 0.049). Our data suggest that in comparison to placebo, a short-term ASA treatment is able to influence the plasma steroid milieu in athletes. Due to the observed variability of the individual hormonal patterns, further research is required to substantiate these findings.

Cortisol, dehydroepiandrosterone sulphate and dehydroepiandrosterone sulphate/cortisol ratio responses to physical stress in males are influenced by pubertal development

To evaluate the influence of chronological age and pubertal development on the hypothalamus-pituitary-adrenal (HPA) axis response to stress, we studied the possible correlations between male pubertal characteristics and salivary cortisol (C), DHEAS and the DHEAS/C ratio before (pre-stress) and after acute exercise-stress in young male volunteers (no. 87; 13.3+/-2.1 yr). In our overall study population, the mean pre-stress salivary C and DHEAS concentrations, significantly increased after exercise-related stress, whereas the DHEAS/C ratio significantly decreased. Pre-stress salivary C was positively correlated with chronological age, and after-stress salivary C concentration variations were negatively correlated with pubertal stage, mean testis volume and pre-stress salivary DHEAS. Furthermore, salivary DHEAS concentrations and the DHEAS/C ratio, before and after exercise stress, were positively correlated with chronological age, pubertal stage, pre-stress salivary testosterone (T), testis volume and body mass index (BMI). In contrast with late pubertal stages (P4, P5), young individuals at early stages of puberty (P1 to P3) showed higher C increase and lower DHEAS/C ratio after exercise-related stress. In conclusion, since C is also a mediator of stress-related negative effects on health and the DHEAS/C ratio has been hypothesized as an index for the degree to which an individual is buffered against the negative effects of stress, these data might suggest potentially increased stress-related risks at early stages of male puberty.

Salivary Steroids at Rest and After a Training Load in Young Male Athletes: Relationship with Chronological Age and Pubertal Development

Puberty influences both the performance and the hormonal responses to exercise-related stress. We evaluated the distribution and the correlation between pubertal characteristics and the salivary cortisol (sC) and testosterone (sT) responses to acute physical exercise in young male athletes (13.4 +/- 2.1 yr, n = 110). The mean pre-exercise nmol . L (-1) sC and sT concentrations were 19.08 +/- 4.32 and 0.34 +/- 0.15 and increased to 21.27 +/- 5.51 and 0.41 +/- 0.16 after a 90-min training session (p < 0.01). The sC concentration at rest was positively correlated with chronological age (p < 0.01) and negatively correlated with fat % (p < 0.05), whereas significant negative correlations of DeltasC and DeltasC% after exercise with age, pubertal stage and mean testis volume (p < 0.05) were observed. The sT increase after exercise was correlated with chronological age, pubertal stage and pre-exercise sT levels (p < 0.01), whereas the DeltasT and DeltasT% of increase were negatively correlated with chronological age and resting sT levels (p < 0.05 and p < 0.01). In the present study, we observed the presence of high inter-individual variability of different biological parameters (anthropometry, pubertal stage, hormones, etc.) within athletes selected by chronological age in the same class and the presence of significant correlations between chronological age, puberty and the steroid hormone responses to physical exercise. Our data suggest the need for different criteria in exercise prescription and selection of young athletes and in the evaluation of stress reactivity at puberty.

Effects of the training status on the hormonal response and recovery from high-intensity isokinetic exercise: comparisons between endurance-trained athletes and sedentary subjects

AIM

Aims of the study were: to determine the differences in the mechanical, hormonal and lactate responses to a high-intensity isokinetic exercise in two groups of endurance-trained athletes (EA, n = 11) and sedentary subjects (SED, n = 11); to evaluate the relationships between the hormonal and lactate responses; to evaluate the effects of the training status on the pituitary responsiveness to the exercise.

METHODS

EA and SED completed, for each leg, 4 sets of 20 maximal concentric contractions of the knee extensor muscle groups at 180 degrees s-1 angular velocity. Blood and saliva for hormonal and lactate determinations were sampled before, immediately after the test and during the subsequent recovery of 2 hours.

RESULTS

The exercise was completed by all subjects and elicited significant mechanical and biochemical responses both in EA and in SED subjects. No differences were found between the two groups both in the mechanical performances and in the increases of lactate and hormones of the pituitary-adrenal axis or in the comparison of the slopes of adrenocorticotropic hormone (ACTH), cortisol, and dehydroepiandrosterone recovery after the peak. The correlation analyses showed significant positive relationships between lactate peak values and percentages of change for ACTH (r2 = 0.16, P < 0.05), salivary cortisol (r2 = 0.42, P < 0.01), and serum cortisol (r2 = 0.56, P < 0.001).

CONCLUSIONS

The adrenocortical activation was found, in this particular setting, at least partly dependent on the muscular lactate production, while no effect of the training status on the pituitary responsiveness to exercise was evident, as it was indirectly confirmed by no abnormalities in the rates of hormonal recovery after the exercise session.

Androgenic-anabolic steroids abuse in males

Androgenic-anabolic steroids (AAS) is an official definition for all male sex steroid hormones, their synthetic derivatives and their active metabolites. AAS are drugs with specific therapeutic indications, yet they are popularly known because of their worldwide non-therapeutic use in a large number of healthy individuals. Doping with AAS has become so widespread in athletics that it affects the outcome of sports contests. Furthermore, AAS non-therapeutic use is increasing particularly among adolescents and females, becoming one of the main causes of iatrogenic diseases due to drug abuse. All physicians must be aware about the large diffusion and side effects related to AAS non-therapeutic use, in order to discover clinical signs of AAS abuse and/or to start adequate preventive and/or therapeutic actions.

Vigorous exercise training is not associated with prevalence of ventricular arrhythmias in elderly athletes

AIM

Physical activity, when vigorous, is not devoided of arrhythmic risk. Since the risk of developing arrhythmias increase as an otherwise healthy person ages, the question arises as to whether high intensity physical activity could be dangerous in the elderly person. The present study addressed the incidence of arrhythmias in elderly athletes in comparison to age-matched control subjects.

METHODS

We studied 49 male athletes engaged in various sport disciplines, mean age 62.3+/-2.3 and 24 sedentary or moderately physically active healthy males, mean age 62.9+/-1.7 years (Controls). All subjects underwent 2-D, M-mode and Doppler echocardiographic examination, resting ECG and exercise stress test followed by 24-hour electrocardiographic monitoring.

RESULTS

No pathological findings were detected in both experimental groups at echocardiographic examination. Exercise performance was greater in athletes than controls (206.9+/-5.2 vs 156.3+/-12 watt, p<0.01). During exercise test, no significant between-groups difference was detected in the incidence of ventricular arrhythmias, that is multiple premature ventricular contractions (MPVC), polymorphous premature ventricular contractions (PPVC) and repetitive premature ventricular contractions (RPVC). No subject featured horizontal or downsloping ST segment depression in both groups. At 24-hour electrocardiographic monitoring the incidence of the overall number of premature ventricular contractions was significantly greater in controls than athletes (87.0% vs 63.3%, p<0.05), whereas no significant difference were detected in the incidence of discrete ventricular arrhythmias between athletes (4.1% MPVC, 14.3% PPVC, 8.2% couplets) and controls (0.5% MPVC, 16.7% PPVC, 12.5% couplets).

CONCLUSION

These finding indicate that in elderly, otherwise healthy, athletes vigorous training even to competition does not result in a greater incidence of ventricular arrhythmias, although caution should be made for a careful preparticipation evaluation.

Heredity and Pituitary Response to Exercise-Related Stress in Trained Men

To evaluate the role of heredity in the pituitary responses to exercise-related stress, serum ACTH, beta-endorphin, cortisol, GH, and PRL responses to a thirty-minute treadmill exercise at individual anaerobic threshold were evaluated in nine pairs of male monozygotic twin athletes. Hormone evaluations were performed before (-30, -15, 0 pre) and after exercise (0 post, + 15, + 30, + 45, + 60, and + 90 min). The intraclass correlation coefficient (expression of within-pair resemblance) was computed for each hormone before and after exercise as area under curves (AUC), absolute values, and percentage of variation, respectively. The exercise-related stress condition induced a significant increase for all evaluated hormones before (anticipatory response) and/or after exercise. As new data, we observed: 1) A significant within-pair resemblance for exercise-related GH and PRL increase (AUCs and/or absolute values), and for the percentage of variation of cortisol, and 2) the lack of significant resemblance for the observed increase of ACTH, cortisol and absolute beta-endorphin serum concentration. This first co-twin control study supports the hypothesis that, in trained men, there are probably different relative roles for the influence of genetic factors on the pituitary hormones involved in physiological adaptation to exercise-related stress. Furthermore, our findings justify further investigations into this topic.

Physical stress and qualitative gonadotropin secretion: LH biological activity at rest and after exercise in trained and untrained men

Sports influence the hypothalamus-pituitary-gonadal axis (HPG). The purpose of this study was to analyze the effects of physical stress on qualitative male LH secretion. We evaluated the HPG axis at rest and the LH response to a treadmill exercise (90 % of Vdot;O 2 max) in eight trained (running 50 to 70 km/week) and eight untrained subjects. FSH, total testosterone (T) and free testosterone (FT) were evaluated at rest by radioimmunoassay, whereas serum LH was evaluated both by radioimmunoassay (I-LH) and by a biological assay (RICT, B-LH), before (-30, -15, 0 pre) and after exercise (0 post, + 15, + 30, + 60 min). Semen analysis was performed. The results showed that the B/I LH ratio was significantly lower at rest in athletes than in controls (1.3 +/- 0.5 and 2.1 +/- 0.7 respectively, p < 0.05) and the B-LH and B/I LH ratio were reduced after exercise in controls (from 21.1 +/- 5.7 to 13.9 +/- 3.4 mIU/mL and from 2.3 +/- 0.8 to 1.6 +/- 0.4, at + 60 respectively, p < 0.05). T and FT were significantly lower in athletes compared with controls (4.18 +/- 1.1 vs 5.96 +/- 1.6 ng/ml and 24.3 +/- 4.8 vs 29.7 +/- 5.2 pg/ml respectively, p < 0.05). Semen parameters showed no difference. The B/I LH ratio could be a "marker" of altered LHRH secretion due to an exercise-linked adaptive condition.

Complex ventricular arrhythmia induced by overuse of potassium supplementation in a young male football player. Case report

People practising regular physical activity usually drink hydrosaline beverages. In this study is reported the case of a young football player suffering from premature ventricular beats. He used to take regularly an hydrosaline supplementation which gave him a daily intake of potassium of about 5 g. A stress test on a cycle ergometer showed many monomorphus premature ventricular beats which disappeared when the heart rate was higher than 110 beats/min. Moreover, 3629 polimorphus premature ventricular beats were recorded during a 24 hr ECG monitoring. At the time of the first examination, the plasma potassium concentration was 7,8 mEq x l(-1). The football player was then suspended from practicing sport and he was asked to stop his intake of potassium. The clinical examination was repeated after 3 and 6 months and no ventricular arrhythmias were observed during the stress test as well as during the 24 hours ECG monitoring. The plasma potassium concentration was normal again. The present case report is an example of how the misuse of saline supplementations could result in hyperkalemia and how this condition may lead to ventricular arrhythmias.

Acetylsalicylic acid inhibits the pituitary response to exercise-related stress in humans

PURPOSE

Prostaglandins (PGs) modulate the activity of the hypothalamus-pituitary axis, and pituitary hormones are largely involved in the physiological responses to exercise. The purpose of this study was to analyze the effects of acetylsalicylic acid (ASA), an inhibitor of PGs synthesis, in the pituitary responses to physical stress in humans.

METHODS

Adrenocorticotropin (ACTH), beta-endorphin, cortisol, growth hormone (GH), and prolactin (PRL) responses to exercise were evaluated after administration of either placebo or ASA. Blood samples for hormone evaluations before (-30, -15, and 0 pre) and after (0 post, +15, +30, +45, +60, and +90 min) a 30-min treadmill exercise (75% of .VO(2max)) were taken from 12 male athletes during two exercise trials. One tablet of ASA (800 mg), or placebo, was administered two times daily for 3 d before and on the morning of each exercise-test.

RESULTS

The results clearly show that, compared with placebo, ASA ingestion significantly blunted the increased serum ACTH, beta-endorphin, cortisol, and GH levels before exercise (anticipatory response) and was associated with reduced cortisol concentrations after exercise. Furthermore, although no differences in the GH response to exercise were shown, a significantly reduced total PRL response to stress condition was observed after ASA.

CONCLUSION

ASA influences ACTH, beta-endorphin, cortisol, GH, and PRL responses to exercise-related stress in humans (preexercise activation/exercise-linked response). Even though it is not possible to exclude direct action for ASA, our data indirectly confirm a role of PGs in these responses. We have to further evaluate the nature of the preexercise endocrine activation and, because of the large use of anti-inflammatory drugs in athletes, whether the interaction between ASA and hormones might positively or negatively influence health status, performance, and/or recovery.

Physical activity as a possible aggravating factor for athletes with varicocele: impact on the semen profile

The aim of the present study was to evaluate the influence of physical exercise on seminal parameters of male athletes with varicocele. Sixty healthy male volunteers (athletes and non-athletes, n = 30 + 30) and 60 volunteers affected by varicocele (athletes and non-athletes, n = 30 + 30) were randomly selected for a clinical study. All subjects provided at least two semen samples for routine microscopic analysis. Determinations for basal luteinizing hormone (LH), follicle stimulating hormone (FSH), prolactin, oestradiol, total and free testosterone under resting conditions were also performed. In both groups with varicocele the percentage of total and progressive forward sperm motility and the percentage of normal spermatozoa were significantly reduced. The percentage of both progressive forward motility and normal spermatozoa were significantly lower in athletes with varicocele compared with non-athletes with varicocele (P < 0.05). Only athletes with varicocele had mean left testis volume significantly lower than the contralateral testis (P < 0.05). No modifications of hormonal parameters at rest were observed in any groups. Physical activity might represent an aggravating factor for spermatogenesis in athletes with varicocele. In countries where sport eligibility is granted by an authoritative body, these results suggest the need to establish general medical criteria to guarantee the continuation of an athlete's training whilst at the same time taking care of his reproductive health.

Effects of aerobic exercise training on 24 hr profile of heart rate variability in female athletes

BACKGROUND

The aim of this study was to investigate the effects of exercise training on autonomic regulation of heart rate under daily life conditions.

METHODS

Twenty-six healthy female athletes (age 24.5 +/- 1.9 yrs) involved in regular physical activity were recruited during a period of yearly rest and randomly assigned to a five-week aerobic exercise training program (n = 13) or to a non-exercise control group (n = 13).

MEASURES

Before and after the five-week training, all subjects underwent a bycicle ergometer stress test and a 24-hour dynamic ECG monitoring. Autonomic regulation of heart rate has been investigated by means of both time and frequency domain analyses of heart rate variability (HRV). Spectral analysis of R-R interval variability (autoregressive algorithm) provided markers of sympathetic (low frequency, LF, 0.10 Hz) and parasympathetic (high frequency, HF, 0.25 Hz) modulation of the sinus node.

RESULTS

Trained subjects showed a reduced heart rate response to submaximal workload. Before training there was no significant difference between the two groups. After training resting heart rate did not significantly differ between trained and untrained subjects. No significant differences were observed in the different time domain indexes of heart rate variability. The day-night difference in SD and SDRR were significantly less in the trained as compared to the untrained group. Normalized LF and HF components did not significantly differ between trained and untrained subjects, during the awake period. The decrease in the LF and the increase in the HF component during nighttime were significantly less in the trained group. The LF/HF ratio was significantly decreased during the night in the untrained group whereas it was not significantly different from the awake state in the trained group.

CONCLUSIONS

These findings of the relative night-time increase in LF and the decrease in the day-night difference in time domain indexes of heart rate variability suggest that, in young female athletes, exercise training is able to induce an increase in the sympathetic modulation of the sinus node which may coexist with signs of relatively reduced, or unaffected, vagal modulation.

Acute effect of physical exercise on serum insulin-like growth factor-binding protein 2 and 3 in healthy men: role of exercise-linked growth hormone secretion

The purpose of this study was to delineate the role of GH on serum IGF-I, IGFBP-2 and -3 responses to exercise. Hormones were evaluated in six trained male subjects before (-30, -15, 0), during (+15) and after (+30, +45, + 60, +90 min) a thirty-minutes treadmill exercise (60% VO2max), both after a single administration of a somatostatin analog (i.e., octreotide, 0.1 mg sc) and after saline. The same evaluations were performed without exercise with similar treatments. The results showed that: 1) octreotide significantly inhibited the GH response to exercise, 2) exercise increased IGFBP-3 concentration (+37.4% at +90, p < 0.05), whereas no modification of IGFBP-2 and of IGF-I/ IGFBP-2 and IGFBP-3/IGFBP-2 ratios were observed, 3) octreotide amplified the IGFBP-3 increase after exercise (p < 0.01 vs. exercise, from + 30 to + 60, or octreotide alone) and, without exercise, slightly increased IGFBP-3 (+15% at +75, p < 0.05) and decreased IGF-I (-14.8% at +75, p < 0.01). We concluded that GH has a reduced role, as a stimulating factor, in the serum acute IGFBP-3 increase after exercise and that octreotide is probably able to directly amplify this response. Unfortunately, we can only speculate on the physiological pathways involved.

Growth hormone and insulin-like growth factor I responses to moderate submaximal acute physical exercise in man: effects of octreotide, a somatostatin analogue, administration

We evaluated growth hormone (GH) and insulin-like growth factor I (IGF-I) response to moderate submaximal acute short-term physical exercise under basal conditions and after the administration of octreotide, a somatostatin analogue (SA), in a double-blind, counter-balanced experimental protocol. Seven untrained male volunteers performed two identical exercise tests, each on a treadmill (2.5% slope) for 30 minutes (min) at 60% of VO2max. Before starting the exercise test all the subjects received a single administration of placebo or octreotide and vice versa at two different sessions. Plasma GH, IGF-I and lactate assays were evaluated before starting, during, at the end and in the recovery phase. In the placebo-treated group GH rose significantly both during exercise and recovery whereas no significant modifications in IGF-I levels were observed. SA administration inhibited the exercise-dependent GH secretion, which showed a small rise only during exercise and returned to basal levels during recovery. In the same group, IGF-I decreased significantly after exercise compared to basal values. The results suggest that 1) in our experimental conditions acute physical exercise at aerobic threshold does not modify IGF-I concentration 2) SA is able to inhibit the exercise-dependent GH secretion and to decrease post-exercise IGF-I concentration.

[Reduced glutathione and anaerobic threshold]

In this study the authors evaluate the relationship existing between reduced glutathione (GSH) and increased indexes of muscle performance. GSH has a protective action on the cell either against the oxidative stress or for its ability of removing through out the body xenobiotic substances circulating. 15 male competitive pentathlon athletes were the sample of this research. The aim of the research is to evaluate the possible role of GSH to determine the anaerobic threshold through its blotting function.

ACTH 1-17 and sexual behavior

The influence of the administration of ACTH 1-17 on the sexual behavior has been studied in a group of male patients affected by psychogenic impotence, i.e. without any detectable organic reason for such disturbance. The administration of the drug led to a notable increase in the sexual performance of the patients. By the way, all the hormonal parameters taken into account (gonadotropins, sexual steroids, adrenal steroids, etc.), were not affected by the treatment. The AA. conclude therefore that the beneficial effect of the ACTH 1-17 on the sexual behavior was due to a direct action on the CNS and was not hormone-mediated.