Analysis of the finasteride treatment and its withdrawal in the rat hypothalamus and hippocampus at whole-transcriptome level

PURPOSE

As reported in patients treated for androgenetic alopecia with finasteride (i.e., a blocker of the enzyme 5 alpha-reductase) and in an animal model, side effects affecting sexual, psychiatric, neurological, and physical domains, may occur during the treatment and persist with drug suspension. The etiopathogenesis of these side effects has been poorly explored. Therefore, we performed a genome-wide analysis of finasteride effects in the brain of adult male rat.

METHODS

Animals were treated (i.e., for 20 days) with finasteride (1mg/rat/day). 24 h after the last treatment and 1 month after drug suspension, RNA sequencing analysis was performed in hypothalamus and hippocampus. Data were analyzed by differential expression analysis and Gene-Set Enrichment Analyses (GSEA).

RESULTS

Data obtained after finasteride treatment showed that 186 genes (i.e., 171 up- and 15 downregulated) and 19 (i.e., 17 up- and 2 downregulated) were differentially expressed in the hypothalamus and hippocampus, respectively. Differential expression analysis at the drug withdrawal failed to identify dysregulated genes. Several gene-sets were enriched in these brain areas at both time points.

CONCLUSION

Some of the genes reported to be differentially expressed (i.e., TTR, DIO2, CLDN1, CLDN2, SLC4A5, KCNE2, CROT, HCRT, MARCKSL1, VGF, IRF2BPL) and GSEA, suggest a potential link with specific side effects previously observed in patients and in the animal model, such as depression, anxiety, disturbance in memory and attention, and sleep disturbance. These data may provide an important background for future experiments aimed at confirming the pathological role of these genes.

Incident Coronary Calcium Score in Patients With OSA With and Without Excessive Sleepiness: Brazilian Longitudinal Study of Adult Health

BACKGROUND

Uncertainty exists about the impact of OSA and its phenotypes on cardiovascular disease.

RESEARCH QUESTION

Are OSA and clinical features such as daytime sleepiness associated with incident subclinical coronary atherosclerosis?

STUDY DESIGN AND METHODS

In this prospective community-based cohort study, we administered a sleepiness questionnaire, actigraphy, and home sleep studies at baseline. Coronary artery calcium (CAC; 64-slice multidetector CT scan imaging) was measured at two different time points throughout the study (baseline, between 2010 and 2014, and follow-up, between 2016 and 2018). Incidence of subclinical atherosclerosis was defined as baseline CAC of 0 followed by CAC of > 0 at a 5-year follow-up visit. The association of incident CAC outcome was assessed using logistic regression. Stratified analyses based on excessive daytime sleepiness (EDS) were performed.

RESULTS

We analyzed 1,956 participants with available CAC scores at baseline (mean age, 49 ± 8 years; 57.9% female; 32.4% with OSA). In covariate-adjusted analyses (n = 1,247; mean follow-up, 5.1 ± 0.9 years), we found a significant association between OSA and incidence of subclinical atherosclerosis (OR, 1.26; 95% CI, 1.06-1.48), with stronger effects among those reporting EDS (OR, 1.66; 95% CI, 1.30-2.12; P = .028 for interaction). Interestingly, EDS per se was not associated with any CAC outcome. An exploratory analysis of the square root of CAC progression (baseline CAC > 0 followed by a numerical increase in scores at follow-up; n = 319) showed a positive association for both OSA (β = 1.084; 95% CI, 0.032-2.136; P = .043) and OSA with EDS (β = 1.651; 95% CI, 0.208-3.094; P = .025).

INTERPRETATION

OSA, particularly with EDS, predicts the incidence and progression of CAC. These results support biological plausibility for the increased cardiovascular risk observed among patients with OSA with excessive sleepiness.

Gender Modulated the Association of Sleep Apnea and Sleep Duration with Arterial Stiffness: The ELSA-Brasil Study

Increased arterial stiffness is independently associated with cardiovascular risk. Obstructive sleep apnea (OSA) and sleep duration (SDUR) may contribute to increased arterial stiffness, but it is unclear whether this association is modulated by gender. We aimed to evaluate the potential impact of gender in modulating the association of OSA and SDUR with arterial stiffness. Participants from the ELSA-Brasil study performed sleep assessments with portable polygraph to define OSA severity and SDUR by 1-week wrist actigraphy. Pulse wave velocity (PWV) was measured using a standard technique without access to the sleep data. We studied 1863 participants (42.2% male, age: 49±8 years, respiratory disturbance index (RDI): 9.9 (4.5-19.4) events/h, SDUR: 6.5 (5.9-7.1) hours, mean PWV: 7.3 ± 1.2 m/s). We found that men had higher PWV, higher frequency of diabetes, and higher blood pressure when compared to women. The regression analysis showed an independent association between increased RDI and PWV in men (ß: 0.007; 95% CI: 0.001-0.012), but not in women. In contrast, an independent association between SDUR and increased arterial stiffness was observed only in women (ß: 0.068; 95% CI: 0.002-0.134). In conclusion, the association of sleep disorders with arterial stiffness showed a distinct gender pattern depending on the sleep variable studied.

Association between objective sleep measures and cognitive performance: a cross-sectional analysis in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) study

Sleep disturbances often co-exist, which challenges our understanding of their potential impact on cognition. We explored the cross-sectional associations of insomnia and objective measures of sleep with cognitive performance in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) study stratified by middle-aged and older adults. Participants aged ≥55 years underwent cognitive evaluations, polygraphy for 1 night, and actigraphy for 7 days. Insomnia was evaluated using the Clinical Interview Scheduled Revised. Obstructive sleep apnea (OSA) and short sleep duration (SSD) were defined by an apnea-hypopnea index (AHI) of ≥15 events/h and <6 h/ night, respectively. In 703 participants (mean [SD] age 62 [6] years, 44% men), cognition was evaluated using a 10-word list, verbal fluency, and trail-making tests. The frequencies of insomnia, SSD, and OSA were 11%, 24%, and 33%, respectively. In all, 4% had comorbid OSA and insomnia, and 11% had both OSA and SSD. Higher wake after sleep onset (β = -0.004, 95% confidence interval [CI] -0.008, -0.001) and the number of awakenings (β = -0.006, 95% CI -0.012, -0.001) were associated with worse verbal fluency performance. Compared to those without insomnia, older participants with insomnia had worse global performance (β = -0.354, 95% CI -0.671, -0.038). Insomnia was an effect modifier in the associations between AHI and executive function performance (p for the interaction between insomnia and AHI = 0.004) and between oxygen saturation <90% and memory performance (p for the interaction between insomnia and oxygen saturation = 0.02). Although some associations between sleep measures and cognition were significant, they should be considered with caution due to the large sample size and multiple testing performed in this study.

Sleep irregularity and the association with hypertension and blood pressure levels: the ELSA-Brasil study

OBJECTIVE

To evaluate the associations of sleep irregularity with hypertension (HTN) and blood pressure (BP) levels.

METHODS

Adult participants from the ELSA-Brasil performed a clinical evaluation including objective sleep duration (actigraphy), insomnia, and a sleep study for defining obstructive sleep apnoea (OSA). To quantify sleep irregularity, we used two parameters obtained through actigraphy: 7-day standard deviation (SD) of sleep duration and 7-day SD of sleep-onset timing. A multivariate analysis was used to determine the independent associations of sleep irregularity with HTN and SBP/DBP values.

RESULTS

We studied 1720 participants (age 49 ± 8 years; 43.4% men) and 27% fulfilled the HTN diagnosis. After adjustments for age, gender, race, BMI, excessive alcohol consumption, physical activity intensity, urinary sodium excretion, insomnia, objective sleep duration and OSA (apnoea-hypopnoea index ≥15 events/h), we found that the continuous analysis of 7-day SD of sleep duration was modestly associated with prevalent HTN. However, 7-day SD of sleep duration more than 90 min was independently associated with SBP [ β : 1.55; 95% confidence interval (CI) 0.23-2.88] and DBP ( β : 1.07; 95% CI 0.12-2.01). Stratification analysis excluding participants with OSA revealed that a 7-day SD of sleep duration greater than 90 min was associated with a 48% higher chance of having HTN (OR: 1.48; 95% CI: 1.05-2.07). No significant associations were observed for the SD of sleep-onset timing.

CONCLUSION

Objective measurement of sleep irregularity, evaluated by SD of sleep duration for 1 week, was associated with HTN and higher BP levels, especially in participants without OSA.

Self-reported versus actigraphy-assessed sleep duration in the ELSA-Brasil study: analysis of the short/long sleep duration reclassification

PURPOSE

This study was aimed to determine the magnitude and predictors of self-reported short/long sleep duration (SDUR) reclassifications using objective measurements.

METHODS

Adult participants from the ELSA-Brasil study performed self-reported SDUR, 7-day wrist actigraphy, and a portable sleep study. We explored two strategies of defining self-reported SDUR reclassification: (1) short and long SDUR defined by <6 and ≥8h, respectively; (2) reclassification using a large spectrum of SDUR categories (<5, 5-6, 7-8, 8-9, and >9 h).

RESULTS

Data from 2036 participants were used in the final analysis (43% males; age: 49±8 years). Self-reported SDUR were poorly correlated (r=0.263) and presented a low agreement with actigraphy-based total sleep time. 58% of participants who self-reported short SDUR were reclassified into the reference (6-7.99 h) or long SDUR groups using actigraphy data. 88% of participants that self-reported long SDUR were reclassified into the reference and short SDUR. The variables independently associated with higher likelihood of self-reported short SDUR reclassification included insomnia (3.5-fold), female (2.5-fold), higher sleep efficiency (1.35-fold), lowest O₂ saturation (1.07-fold), higher wake after sleep onset (1.08-fold), and the higher number of awakening (1.05-fold). The presence of hypertension was associated with a 3.4-fold higher chance of self-reported long SDUR reclassification. Analysis of five self-reported SDUR categories revealed that the more extreme is the SDUR, the greater the self-reported SDUR reclassification.

CONCLUSION

In adults, we observed a significant rate of short/long SDUR reclassifications when comparing self-reported with objective data. These results underscore the need to reappraise subjective data use for future investigations addressing SDUR.

Alterations of gut microbiota composition in post-finasteride patients: a pilot study

PURPOSE

Post-finasteride syndrome (PFS) has been reported in a subset of patients treated with finasteride (an inhibitor of the enzyme 5alpha-reductase) for androgenetic alopecia. These patients showed, despite the suspension of the treatment, a variety of persistent symptoms, like sexual dysfunction and cognitive and psychological disorders, including depression. A growing body of literature highlights the relevance of the gut microbiota-brain axis in human health and disease. For instance, alterations in gut microbiota composition have been reported in patients with major depressive disorder. Therefore, we have here analyzed the gut microbiota composition in PFS patients in comparison with a healthy cohort.

METHODS

Fecal microbiota of 23 PFS patients was analyzed by 16S rRNA gene sequencing and compared with that reported in ten healthy male subjects.

RESULTS

Sexual dysfunction, psychological and cognitive complaints, muscular problems, and physical alterations symptoms were reported in more than half of the PFS patients at the moment of sample collection. The quality sequence check revealed a low library depth for two fecal samples. Therefore, the gut microbiota analyses were conducted on 21 patients. The α-diversity was significantly lower in PFS group, showing a reduction of richness and diversity of gut microbiota structure. Moreover, when visualizing β-diversity, a clustering effect was found in the gut microbiota of a subset of PFS subjects, which was also characterized by a reduction in Faecalibacterium spp. and Ruminococcaceae UCG-005, while Alloprevotella and Odoribacter spp were increased compared to healthy control.

CONCLUSION

Gut microbiota population is altered in PFS patients, suggesting that it might represent a diagnostic marker and a possible therapeutic target for this syndrome.

Obstructive sleep apnea is associated with lower adiponectin and higher cholesterol levels independently of traditional factors and other sleep disorders in middle-aged adults: the ELSA-Brasil cohort

PURPOSE

Obstructive sleep apnea (OSA) may contribute to metabolic and inflammatory deregulation but previous studies failed to consider sleep duration, sleep fragmentation, insomnia, and daytime sleepiness as potential confounders.

METHODS

Consecutive non-diabetic middle-aged participants from the ELSA-Brasil cohort were invited to perform a clinical evaluation, home sleep study for 1 night, and wrist actigraphy for 7 days. OSA was defined by an apnea-hypopnea index ≥ 15 events/h. Participants were stratified according to the presence of OSA measuring the following markers: fasting glucose, glucose tolerance test, homeostatic model assessment of insulin resistance (HOMA-IR) index, fasting insulin, insulin after 2 h of glucose load, glycated hemoglobin, total cholesterol and their fractions, triglycerides, C-reactive protein, TNF-alpha, interleukin-6, interleukin-10, leptin, adiponectin, E-selectin, ADMA, MCP-1, TGF, apolipoprotein B, fibrinogen, and lipoprotein(a). Differences between groups were identified by chi-square test and ANOVA.

RESULTS

We studied 708 participants (mean age: 46 ± 5 years, men: 44%, BMI 26.1 ± 4.1 kg/m²). Compared to no OSA, participants with OSA presented higher levels while fasting and after 2 h glucose load of insulin, HOMA-IR, cholesterol, triglycerides, and C-reactive protein (all p < 0.001). After linear regression analysis adjusting for traditional risk factors plus sleep duration, fragmentation, insomnia, and daytime sleepiness, OSA was negatively associated with adiponectin (β = - 0.271 CI 95% - 0.456 - 0.085) and positively associated with cholesterol (β = 9.707 CI 95% 2.737 16.678). Sex-stratification revealed that these associations were significant for men but not women.

CONCLUSIONS

In non-diabetic middle-age adults, men with OSA presented with lower adiponectin and higher cholesterol levels independently of sleep duration, sleep fragmentation, insomnia, and daytime sleepiness.

Obstructive Sleep Apnea, Sleep Duration, and Associated Mediators With Carotid Intima-Media Thickness: The ELSA-Brasil Study

[Figure: see text].

Steroidogenic machinery in the adult rat colon

Gastrointestinal function is known to be regulated by steroid molecules produced by the gonads, the adrenal glands and the gut microbiota. However, we have a limited knowledge on the functional significance of local steroid production by gastrointestinal tract tissue. On this basis, we have here evaluated, as a first methodological approach, the expression of steroidogenic molecules and the local levels of key steroids in the male rat colon. Our findings indicate that the colon tissue expresses molecules involved in the early steps of steroidogenesis and in the consecutive synthesis and metabolism of steroid hormones, such as progesterone, testosterone and 17β-estradiol. In addition, the levels of the steroid hormone precursor pregnenolone and the levels of active metabolites of progesterone and testosterone, such as dihydroprogesterone, tetrahydroprogesterone, dihydrotestosterone and 17β-estradiol, were higher in colon than in plasma. Higher levels of the androgen metabolite 3α-diol were detected in the colon in comparison with another non-classical steroidogenic tissue, such as the cerebral cortex. These findings suggest the existence of local steroid synthesis and metabolism in the colon, with the production of active steroid metabolites that may impact on the activity of the enteric nervous system and on the composition of the gut microbiota.

Sex dimorphism in an animal model of multiple sclerosis: Focus on pregnenolone synthesis

Neuroactive steroids, molecules produced from cholesterol in steroidogenic cells (i.e., peripheral glands and nervous system) are physiological modulators and protective agents of nervous function. A possible role for neuroactive steroids in the sex-dimorphic clinical manifestation, onset and progression of Multiple Sclerosis (MS) has been recently suggested. To explore this possibility, we assessed the synthesis of the first steroidogenic product (pregnenolone; PREG) in the spinal cord of experimental autoimmune encephalomyelitis rats, a MS model. Data obtained indicate that the synthesis of PREG in the spinal cord is altered by the pathology in a sex-dimorphic way and depending on the pathological progression. Indeed, in male spinal cord the synthesis was already decreased at the acute phase of the disease (i.e., 14 days post induction - dpi) and maintained low during the chronic phase (i.e., 45 dpi), while in females this effect was observed only at the chronic phase. Substrate availability had also a role in the sex-dimorphic kinetics. Indeed, at the chronic phase, male animals showed a reduction in the levels of free cholesterol coupled to alteration of cholesterol metabolism into oxysterols; these effects were not observed in female animals. These findings suggest that the comprehension of the neurosteroidogenic processes could be relevant to better understand the sexual dimorphism of MS and to possibly design sex-oriented therapeutic strategies based on neuroactive steroids.

P6547The energy cost of His bundle pacing can be curtailed

Introduction

His bundle pacing (HBP) allows physiological ventricular activation and prevents the electrical and mechanical desynchronization generally induced by myocardial stimulation, which can increase the risk of atrial fibrillation and heart failure. On the other hand, reliable HBP capture often requires higher energy than conventional myocardial pacing. This reduces the expected life of the stimulator and might limit the diffusion of HBP in the clinical practice.

Purpose

Decreasing HBP current drain by careful management of stimulation safety margin and pulse duration.

Methods

In 28 patients undergoing DDD pacing with HBP, a third lead was implanted in RV apex to provide back-up pacing on demand. HBP and apical leads were connected, respectively, to the V1 and V2 channels of a 3-chamber stimulator. When HBP was effective, apical sensing occurred within the VV delay and prevented V2 stimulation. In contrast, in case of HBP failure, V2 sensing was missing and apical back-up pacing was promptly delivered at the end of the VV delay. The availability of a back-up pulse on demand allowed reducing the HBP safety margin with no risk. Furthermore, the individual HBP strength-duration curve was derived in the aim of optimizing the Hisian pulse parameters, which are the major determinants of the device current drain.

Results

Correct back-up inhibition by successful HBP and stimulation in the event of capture loss was achieved in all the patients. The latency from Hisian pacing to apical sensing averaged 96±14 ms. According to the pacemaker counters, no back-up pulse was delivered in daily life in 59% of patients. In the remaining, the prevalence of back-up stimulation never exceeded 15% of paced ventricular cycles. The high HBP threshold was essentially due to an increased rheobase (1.2±0.6 V), while the chronaxie ranged from 0.30 to 0.53 ms in 71% of patients (median 0.44 ms), exceeding 0.6 ms only in 29% of the cases. An average current saving of 5.4±3.0 μA was obtained at the expense of a mild reduction in HBP safety margin (from 1.6±0.2 to 1.4±0.1 times).

HBP and apical back-up

Conclusions

Back-up stimulation on demand is a reliable option to decrease HBP current drain and prolong the stimulator service life with full safety. In most of the cases, significant saving can be achieved by pulse shortening, as the chronaxie time is in the same range as with myocardial stimulation and longer pulses are not required. A pulse duration exceeding 0.6 ms is indicated in less than 1/3 of the implants.

Accuracy of global and/or regional anthropometric measurements of adiposity in screening sleep apnea: the ELSA-Brasil cohort

OBJECTIVE

Adiposity is a well-established risk factor for obstructive sleep apnea (OSA) but the existence of a preferable anthropometric measurement is not established or whether the combination of measurements may improve the accuracy to detect OSA. This study aimed to compare the accuracies of body mass index (BMI), several surrogate markers of body fat (in isolation or combined) and validated questionnaires for screening OSA.

METHODS

A total of 2059 participants from the ELSA-Brasil study given anthropometric measurements using standard procedures and a home sleep study. OSA was defined by an apnea-hypopnea index ≥15 events/hour.

RESULTS

The frequency of OSA was 32.3%. Compared with the non-OSA group, all anthropometric measurements were higher in the OSA group. Age and gender-adjusted BMI afforded the highest accuracy to detect OSA [AUC = 0.760 (0.739-0.781)], followed by waist [AUC = 0.753 (0.732-0.775)] and neck [AUC = 0.733 (0.711-0.755)] circumferences, waist-to-hip ratio [AUC = 0.722 (0.699-0.745)] and body shape index [AUC = 0.680 (0.656-0.704)]. The combination of two or more anthropometric measurements did not improve the accuracy of BMI in predicting OSA. The adjusted BMI had similar predictive performance to the NoSAS score [AUC = 0.748 (0.727-0.770)] but a better accuracy than the Berlin Questionnaire [AUC = 0.676 (0.653-0.699)].

CONCLUSIONS

Despite one's intuition, surrogate markers of regional adiposity are not better than BMI in screening OSA. Combining measurements of global and/or regional adiposity did not have additional value in detecting OSA. The merely fair accuracy range of BMI and sleep questionnaires underscore the need for additional tools to improve OSA underdiagnosis.

Pragmatic Validation of Home Portable Sleep Monitor for diagnosing Obstructive Sleep Apnea in a non-referred population: The ELSA-Brasil study

Objective

Polygraphy (PG) is an attractive alternative for diagnosing obstructive sleep apnea (OSA) in patients with high pre-test probability. However, several patients may not present typical symptoms. In this scenario, it is unclear the performance of PG for diagnosing OSA in non-referred populations to sleep laboratories.

Methods

Data from participants of the ELSA-Brasil cohort were used for this analysis. We performed an overnight home PG (Embletta Gold^TM) synchronized with a wrist actigraphy (Actiwatch model 2^TM). The validation strategy comprised three scorings from each participant: 1) Original scoring (PG): Routine scoring using data from the exclamation button mark to define “analysis start” and “analysis stop”; 2) Scoring using actigraphy data (PG+actigraphy): total sleep time defined by the actigraphy data; 3) Scoring using diaries (PG+diary): “analysis start” and “analysis stop” based on the diaries. Bland-Altman plots were generated to assess the agreements (Kappa) between each scoring strategy.

Results

A total of 300 participants were included in the final analysis (45% males, mean age: 48±8 years). The frequency of OSA using the PG score was 27.3%. Despite small differences in the OSA severity index, we obtained a high concordance of AHI comparing the PG vs. PG+actigraphy (Kappa: 0.95) as well as PG+diary vs. PG+actigraphy (Kappa: 0.96). No significant changes in the OSA classification (mild, moderate and severe) were observed in the 3 protocols.

Conclusion

Using a pragmatic approach to address OSA at home, our results suggest that PG is a useful tool for OSA diagnosis even in subjects not referred to sleep studies.

Neuroactive steroids and diabetic complications in the nervous system

Important complications of diabetes mellitus in the nervous system are represented by diabetic peripheral neuropathy and diabetic encephalopathy. In this context, an important link is represented by neuroactive steroids (i.e., steroids coming from peripheral glands and affecting nervous functionality as well as directly synthesized in the nervous system). Indeed, diabetes does not only affect the reproductive axis and consequently the levels of sex steroid hormones, but also those of neuroactive steroids. Indeed, as will be here summarized, the levels of these neuromodulators present in the central and peripheral nervous system are affected by the pathology in a sex-dimorphic way. In addition, some of these neuroactive steroids, such as the metabolites of progesterone or testosterone, as well as pharmacological tools able to increase their levels have been demonstrated, in experimental models, to be promising protective agents against diabetic peripheral neuropathy and diabetic encephalopathy.

Trattamento percutaneo dell'ernia discale lombare con iniezione intradiscale di miscela di ozono

Negli ultimi anni si sono moltiplicate le segnalazioni dell'utilità dell'ossigeno-ozono terapia intradiscale, che abbiamo iniziato nel 1997 con iniezione intradiscale e paraspinale.

Dal Dicembre 1997 all'Agosto 2000 sono stati trattati 444 pazienti, di cui maschi 240 e femmine 204, per complessivi 723 trattamenti.

Vengono qui presentati 191 pazienti sottoposti a trattamento con unica seduta, dei quali si è completato il controllo a sei mesi.

Nel complesso i risultati ottimi - buoni raggiungono un livello percentuale che è appena inferiore a quello ottenibile con chemonucleolisi enzimatica; l'introduzione della ossigeno ozono terapia intradiscale nella nostra pratica clinica si è rivelata sicuramente positiva.

Neuroprotective effects of progesterone in chronic experimental autoimmune encephalomyelitis

Observations so far obtained in experimental autoimmune encephalomyelitis (EAE) have revealed the promising neuroprotective effects exerted by progesterone (PROG). The findings suggest that this neuroactive steroid may potentially represent a therapeutic tool for multiple sclerosis (MS). However, up to now, the efficacy of PROG has been only tested in the acute phase of the disease, whereas it is well known that MS expresses different features depending on the phase of the disease. Accordingly, we have evaluated the effect of PROG treatment in EAE induced in Dark Agouti rats (i.e. an experimental model showing a protracted relapsing EAE). Data obtained 45 days after EAE induction show that PROG treatment exerts a beneficial effect on clinical score, confirming surrogate parameters of spinal cord damage in chronic EAE (i.e. reactive microglia, cytokine levels, activity of the Na(+) ,K(+) -ATPase pump and myelin basic protein expression). An increase of the levels of dihydroprogesterone and isopregnanolone (i.e. two PROG metabolites) was also observed in the spinal cord after PROG treatment. Taken together, these results indicate that PROG is effective in reducing the severity of chronic EAE and, consequently, may have potential with respect to MS treatment.

Effect of short-and long-term gonadectomy on neuroactive steroid levels in the central and peripheral nervous system of male and female rats

Significant levels of neuroactive steroids are still detected in the nervous system of rodents after the removal of peripheral steroidogenic glands. However, the influence of the plasma levels of gonadal steroids on the levels of neuroactive steroids in the nervous system has not so far been clarified in detail. Accordingly, by liquid chromatography tandem mass spectrometry, we have analysed the levels of neuroactive steroids in the sciatic nerve, in three central nervous system (CNS) regions (i.e. cerebellum, cerebral cortex and spinal cord) and in the plasma of male and female animals. The levels present in gonadally intact animals were compared with those present in short- and long-term gonadectomised animals. We observed that: (i) changes in neuroactive steroid levels in the nervous system after gonadectomy do not necessarily reflect the changes in plasma levels; (ii) long-term gonadectomy induces changes in the levels of neuroactive steroids in the peripheral nervous system (PNS) and the CNS that, in some cases, are different to those induced by short-term gonadectomy; (iii) the effect of gonadectomy on neuroactive steroid levels is different between the PNS and the CNS and within different CNS regions; and (iv) the effects of gonadectomy on neuroactive steroid levels in the nervous system show sex differences. Altogether, these observations indicate that the nervous system adapts its local levels of neuroactive steroids in response to changes in gonadal hormones with sex and regional specificity and depending on the duration of the peripheral modifications.

Testosterone derivatives are neuroprotective agents in experimental diabetic neuropathy

In this study we have assessed the effect of testosterone (T), dihydrotestosterone (DHT) and 5alphaandrostan-3alpha, 17beta-diol (3alpha-diol) therapies on diabetic neuropathy. Diabetes was induced in adult male rats by the injection of streptozotocin and resulted in decreased T and increased 3alpha-diol levels in plasma and in decreased levels of pregnenolone and DHT in the sciatic nerve. Moreover, a reduced expression of the enzyme converting Tinto DHT (i.e., the 5alpha-reductase) also occurs at the level of sciatic nerve, suggesting that the decrease of DHT levels could be due to an impairment of this enzyme. Chronic treatment for 1 month with DHT or 3alpha-diol increased tail nerve conduction velocity and partially counteracted the increase of thermal threshold induced by diabetes. Treatment with DHT increased tibial Na(+),K(+)-ATPase activity and the expression of myelin protein P0 in the sciatic nerve.DHT, 3alpha-diol and T reversed the reduction of intra-epidermal nerve fiber density induced by diabetes. These observations indicate that T metabolites can reverse behavioral, neurophysiological, morphological and biochemical alterations induced by peripheral diabetic neuropathy.