Experimental hyperprolinemia induces mild oxidative stress, metabolic changes, and tissue adaptation in rat liver

The present study investigated the effects of chronic hyperprolinemia on oxidative and metabolic status in liver and serum of rats. Wistar rats received daily subcutaneous injections of proline from their 6th to 28th day of life. Twelve hours after the last injection the rats were sacrificed and liver and serum were collected. Results showed that hyperprolinemia induced a significant reduction in total antioxidant potential and thiobarbituric acid-reactive substances. The activities of the antioxidant enzymes catalase and superoxide dismutase were significantly increased after chronic proline administration, while glutathione (GSH) peroxidase activity, dichlorofluorescin oxidation, GSH, sulfhydryl, and carbonyl content remained unaltered. Histological analyses of the liver revealed that proline treatment induced changes of the hepatic microarchitecture and increased the number of inflammatory cells and the glycogen content. Biochemical determination also demonstrated an increase in glycogen concentration, as well as a higher synthesis of glycogen in liver of hyperprolinemic rats. Regarding to hepatic metabolism, it was observed an increase on glucose oxidation and a decrease on lipid synthesis from glucose. However, hepatic lipid content and serum glucose levels were not changed. Proline administration did not alter the aminotransferases activities and serum markers of hepatic injury. Our findings suggest that hyperprolinemia alters the liver homeostasis possibly by induction of a mild degree of oxidative stress and metabolic changes. The hepatic alterations caused by proline probably do not implicate in substantial hepatic tissue damage, but rather demonstrate a process of adaptation of this tissue to oxidative stress. However, the biological significance of these findings requires additional investigation. J. Cell. Biochem. 113: 174183, 2012. (C) 2011 Wiley Periodicals, Inc.

Physiological responses and rate of perceived exertion in Brazilian jiu-jitsu athletes

In this study, the physiological responses and rate of perceived exertion in Brazilian jiu-jitsu fighters submitted to a combat simulation were investigated. Venous blood samples and heart rate were taken from twelve male Brazilian jiu-jitsu athletes (27.1+/-2.7 yrs, 75.4+/-8.8 kg, 174.9+/-4.4 cm, 9.2+/-2.4% fat), at rest, after a warm-up (ten minutes), immediately after the fight simulation (seven minutes) and after recovery (fourteen minutes). After the combat the rate of perceived exertion was collected. The combat of the Brazilian jiu-jitsu fighters did not change blood concentrations of glucose, triglycerides, total cholesterol, low density lipoprotein and very low density lipoprotein, ureia and ammonia. However, blood levels of high density lipoprotein were significantly higher post-fight (before: 43.0+/-6.9 mg/dL, after: 45.1+/-8.0 mg/dL) and stayed at high levels during the recovery period (43.6+/-8.1 mg/dL) compared to the rest values (40.0+/-6.6 mg/dL). The fight did not cause changes in the concentrations of the cell damage markers of creatine kinase, aspartate aminotransferase and creatinine. However, blood concentrations of the alanine aminotransferase (before: 16.1+/-7.1 U/L, after: 18.6+/-7.1 U/L) and lactate dehydrogenase (before: 491.5+/-177.6 U/L, after: 542.6+/-141.4 U/L) enzymes were elevated after the fight. Heart rate (before: 122+/-25 bpm, after: 165+/-17 bpm) and lactate (before: 2.5+/-1.2 mmol/L, after: 11.9+/-5.8 mmol/L) increased significantly with the completion of combat. Despite this, the athletes rated the fight as being light or somewhat hard (12+/-2). These results showed that muscle glycogen is not the only substrate used in Brazilian jiu-jitsu fights, since there are indications of activation of the glycolytic, lipolytic and proteolytic pathways. Furthermore, the athletes rated the combats as being light or somewhat hard although muscle damage markers were generated.

Does Lithium Prevent Alzheimer's Disease?

Lithium salts have a well-established role in the treatment of major affective disorders. More recently, experimental and clinical studies have provided evidence that lithium may also exert neuroprotective effects. In animal and cell culture models, lithium has been shown to increase neuronal viability through a combination of mechanisms that includes the inhibition of apoptosis, regulation of autophagy, increased mitochondrial function, and synthesis of neurotrophic factors. In humans, lithium treatment has been associated with humoral and structural evidence of neuroprotection, such as increased expression of anti-apoptotic genes, inhibition of cellular oxidative stress, synthesis of brain-derived neurotrophic factor (BDNF), cortical thickening, increased grey matter density, and hippocampal enlargement. Recent studies addressing the inhibition of glycogen synthase kinase-3 beta (GSK3B) by lithium have further suggested the modification of biological cascades that pertain to the pathophysiology of Alzheimer's disease (AD). A recent placebo-controlled clinical trial in patients with amnestic mild cognitive impairment (MCI) showed that long-term lithium treatment may actually slow the progression of cognitive and functional deficits, and also attenuate Tau hyperphosphorylation in the MCI-AD continuum. Therefore, lithium treatment may yield disease-modifying effects in AD, both by the specific modification of its pathophysiology via inhibition of overactive GSK3B, and by the unspecific provision of neurotrophic and neuroprotective support. Although the clinical evidence available so far is promising, further experimentation and replication of the evidence in large scale clinical trials is still required to assess the benefit of lithium in the treatment or prevention of cognitive decline in the elderly.

Synthesis of 1,2,3-triazolylpyranosides through click chemistry reaction

We have developed an efficient method for the synthesis of functionalized C-glycosyl 1,2,3-triazoles through a Cu(1)-promoted azide-alkyne 1,3-dipolar cycloaddition between a TMS-protected C-alkynyl-glycoside and organic azides. The reaction was accelerated by ultrasound irradiation and the addition of a base was not necessary to obtain the 1,2,3-triazole product. Moreover, further manipulation of the products led to chiral molecules with a C-glycoside linkage. (C) 2012 Elsevier Ltd. All rights reserved.

Proposal of non-invasive experimental model to induce scoliosis in rats

Background: In the literature, there are several experimental models that induce scoliosis in rats; however, they make use of drugs or invasive interventions to generate a scoliotic curve. Objectives: To design and apply a non-invasive immobilization model to induce scoliosis in rats. Methods: Four-week old male Wistar rats (85 +/- 3.3 g) were divided into two groups: control (CG) and scoliosis (SG). The animals in the SG were immobilized by two vests (scapular and pelvic) made from polyvinyl chloride (PVC) and externally attached to each other by a retainer that regulated the scoliosis angle for twelve weeks with left convexity. After immobilization, the abdominal, intercostal, paravertebral, and pectoral muscles were collected for chemical and metabolic analyses. Radiographic reports were performed every 30 days over a 16-week period. Results: The model was effective in the induction of scoliosis, even 30 days after immobilization, with a stable angle of 28 +/- 5 degrees. The chemical and metabolic analyses showed a decrease (p<0.05) in the glycogenic reserves and in the relationship between DNA and total protein reserves of all the muscles analyzed in the scoliosis group, being lower (p<0.05) in the convex side. The values for the Homeostatic Model Assessment of Insulin Resistance indicated a resistance condition to insulin (p<0.05) in the scoliosis group (0.66 +/- 0.03), when compared to the control group (0.81 +/- 0.02). Conclusions: The scoliosis curvature remained stable 30 days after immobilization. The chemical and metabolic analyses suggest changes in muscular homeostasis during the induced scoliosis process.

Expression of angiogenic factors in placenta of stressed rats

The aim of the present study was to analyse the influence of stress on pregnant rats, particularly in terms of maternal, placental and fetal weight, placental morphology and placental gene expression of the angiogenic factors Vegfa and Pgf and their receptors. The parameters were evaluated on gestation Day 20. Maternal, fetal and placental weights were statistically lower in stressed animals than controls, suggesting abnormalities in gestational physiology. Morphologically the placentas of rats subjected to stress were reduced in size and weight, with few glycogen cells and a significant increase in the number of apoptotic cells. Stress caused an increase in placental gene expression of Vegfa (P < 0.05) and a reduction in Pgf, Flt1 and Kdr expression (P < 0.05). It has been suggested that increased VEGF is associated with vasodilatation and hypotension, but in this model persistent hypertension was present. This study suggests that the limited hypotensive Vegfa response to stress-induced hypertension could result from reduced expression of Flt1/Kdr disrupting specific VEGF pathways. These findings may elucidate one of the multiple possible factors underlying how stress modulates placental physiology, and could aid the understanding of stress-induced gestational disorders.

Effects of Diets Supplemented with Branched-Chain Amino Acids on the Performance and Fatigue Mechanisms of Rats Submitted to Prolonged Physical Exercise

This study aimed to determine the effects of diets chronically supplemented with branched-chain amino acids (BCAA) on the fatigue mechanisms of trained rats. Thirty-six adult Wistar rats were trained for six weeks. The training protocol consisted of bouts of swimming exercise (one hour a day, five times a week, for six weeks). The animals received a control diet (C) (n = 12), a diet supplemented with 3.57% BCAA (S1) (n = 12), or a diet supplemented with 4.76% BCAA (S2) (n = 12). On the last day of the training protocol, half the animals in each group were sacrificed after one hour of swimming (1H), and the other half after a swimming exhaustion test (EX). Swimming time until exhaustion was increased by 37% in group S1 and reduced by 43% in group S2 compared to group C. Results indicate that the S1 diet had a beneficial effect on performance by sparing glycogen in the soleus muscle (p < 0.05) and by inducing a lower concentration of plasma ammonia, whereas the S2 diet had a negative effect on performance due to hyperammonemia (p < 0.05). The hypothalamic concentration of serotonin was not significantly different between the 1H and EX conditions. In conclusion, chronic BCAA supplementation led to increased performance in rats subjected to a swimming test to exhaustion. However, this is a dose-dependent effect, since chronic ingestion of elevated quantities of BCAA led to a reduction in performance.

Different approaches, one target: understanding cellular mechanisms of Parkinson's and Alzheimer's diseases

Neurodegenerative disorders are undoubtedly an increasing problem in the health sciences, given the increase of life expectancy and occasional vicious life style. Despite the fact that the mechanisms of such diseases are far from being completely understood, a large number of studies; that derive from both the basic science and clinical approaches have contributed substantial data in that direction. In this review, it is discussed several frontiers of basic research on Parkinson's and Alzheimer's diseases, in which research groups from three departments of the Institute of Biomedical Sciences of the University of Sao Paulo have been involved in a multidisciplinary effort. The main focus of the review involves the animal models that have been developed to study cellular and molecular aspects of those neurodegenerative diseases, including oxidative stress, insulin signaling and proteomic analyses, among others. We anticipate that this review will help the group determine future directions of joint research in the field and, more importantly, set the level of cooperation we plan to develop in collaboration with colleagues of the Nucleus for Applied Neuroscience Research that are mostly involved with clinical research in the same field.

Early and late neurodegeneration and memory disruption after intracerebroventricular streptozotocin

Glucose metabolism and insulin signaling disruptions in the brain have been proposed as a likely etiology of Alzheimer's disease. The aim of the present study was to investigate the time course of cognitive impairments induced by intracerebroventricular injection of streptozotocin (STZ) in rats and correlate them with the ensuing neurodegenerative process. Early and late effects of STZ were evaluated by using the reference and working memory versions of the Morris' water maze task and the evaluation of neurodegenerative markers by immunoblotting and the Fluoro-jade C histochemistry. The results revealed different types of behavioral and neurodegenerative responses, with distinct time courses. We observed an early disruption on the working memory as early as 3 h after STZ injections, which was followed by degenerative processes in the hippocampus at 1 and 15 days after STZ injections. Memory disruption increases over time and culminates with significant changes in amyloid-beta peptide and hyperphosphorylated Tau protein levels in distinct brain structures. These findings add information on the Alzheimer's disease-like STZ animal model and on the mechanisms underlying neurodegenerative processes. (C) 2012 Elsevier Inc. All rights reserved.

Sanguineous normothermic, intermittent cardioplegia, effects on hypertrophic myocardium: morphometric, metabolic and ultrastructural studies in rabbits hearts

OBJECTIVES: The present investigation aimed to study the protective effect of intermittent normothermic cardioplegia in rabbit's hypertrophic hearts. METHODS: The parameters chosen were 1) the ratio heart weight / body weight, 2) the myocardial glycogen levels, 3) ultrastructural changes of light and electron microscopy, and 4) mitochondrial respiration. RESULTS: 1) The experimental model, coarctation of the aorta induced left ventricular hypertrophy; 2) the temporal evolution of the glycogen levels in hypertrophic myocardium demonstrates that there is a significant decrease; 3) It was observed a time-dependent trend of higher oxygen consumption values in the hypertrophic group; 4) there was a significant time-dependent decrease in the respiratory coefficient rate in the hypertrophic group; 5) the stoichiometries values of the ADP: O2 revealed the downward trend of the values of the hypertrophic group; 6) It was possible to observe damaged mitochondria from hypertrophic myocardium emphasizing the large heterogeneity of data. CONCLUSION: The acquisition of biochemical data, especially the increase in speed of glycogen breakdown, when anatomical changes are not detected, represents an important result even when considering all the difficulties inherent in the process of translating experimental results into clinical practice. With regard to the adopted methods, it is clear that morphometric methods are less specific. Otherwise, the biochemical data allow detecting alterations of glycogen concentrations and mitochondria respiration before the morphometric alterations should be detected

Revisão sistemática das escalas utilizadas para avaliação funcional na doença de Pompe

OBJETIVO: Identificar as escalas utilizadas para avaliação funcional na doença de Pompe (DP) e descrever seu nível de evidência e recomendação. FONTES DE DADOS: Revisão sistemática sobre as escalas de avaliação funcional na DP. Pesquisa realizada nos bancos de dados Medline, Lilacs, Registro Cochrane de Ensaios Controlados Central (CCTR) e SciELO com artigos (exceto artigos de revisão) publicados entre 2000 e 2010. As palavras-chave utilizadas nos idiomas português e inglês foram: doença de depósito de glicogênio tipo II, atividades cotidianas, avaliação. Os artigos foram classificados em nível de evidência e recomendação. SÍNTESE DOS DADOS: Foram incluídos 14 estudos que avaliaram desde recém-nascidos a adultos (amostra total=449). Foram encontradas as seguintes escalas na literatura: Pediatric Evaluation of Disability Inventory (PEDI) e sua forma adaptada para DP (Pompe-PEDI), Alberta Infant Motor Scale (AIMS), Rotterdam Handiscap Scale (RHS), Functional Independence Measure (FIM), Gross Motor Function Measure (GMFM) e Peabody Developmental Motor Scales (PDMS-II). A maioria dos estudos apresentou nível de evidência III, por serem não randomizados. Grau de recomendação das escalas: C para AIMS e Pompe-PEDI; D para GMFM e PDMS-II; E para RHS e FIM. CONCLUSÕES: A maioria das escalas utilizadas para avaliação funcional na DP apresenta baixo nível de evidência e recomendação. As que apresentam melhor grau de recomendação (C) são as escalas AIMS e Pompe-PEDI aplicadas em Pediatria.

Adaptations of the aging animal to exercise: role of daily supplementation with melatonin

The pineal gland, through melatonin, seems to be of fundamental importance in determining the metabolic adaptations of adipose and muscle tissues to physical training. Evidence shows that pinealectomized animals fail to develop adaptive metabolic changes in response to aerobic exercise and therefore do not exhibit the same performance as control-trained animals. The known prominent reduction in melatonin synthesis in aging animals led us to investigate the metabolic adaptations to physical training in aged animals with and without daily melatonin replacement. Male Wistar rats were assigned to four groups: sedentary control (SC), trained control (TC), sedentary treated with melatonin (SM), and trained treated with melatonin (TM). Melatonin supplementation lasted 16 wk, and the animals were subjected to exercise during the last 8 wk of the experiment. After euthanasia, samples of liver, muscle, and adipose tissues were collected for analysis. Trained animals treated with melatonin presented better results in the following parameters: glucose tolerance, physical capacity, citrate synthase activity, hepatic and muscular glycogen content, body weight, protein expression of phosphatidylinositol 3-kinase (PI3K), mitogen-activated protein kinase (MAPK), and protein kinase activated by adenosine monophosphate (AMPK) in the liver, as well as the protein expression of the glucose transporter type 4 (GLUT4) and AMPK in the muscle. In conclusion, these results demonstrate that melatonin supplementation in aging animals is of great importance for the required metabolic adaptations induced by aerobic exercise. Adequate levels of circulating melatonin are, therefore, necessary to improve energetic metabolism efficiency, reducing body weight and increasing insulin sensitivity.

Metabolic and thermodynamic responses to dehydration-induced reductions in muscle blood flow in exercising humans

[EN] 1. The present study examined whether reductions in muscle blood flow with exercise-induced dehydration would reduce substrate delivery and metabolite and heat removal to and from active skeletal muscles during prolonged exercise in the heat. A second aim was to examine the effects of dehydration on fuel utilisation across the exercising leg and identify factors related to fatigue. 2. Seven cyclists performed two cycle ergometer exercise trials in the heat (35 C; 61 +/- 2 % of maximal oxygen consumption rate, VO2,max), separated by 1 week. During the first trial (dehydration, DE), they cycled until volitional exhaustion (135 +/- 4 min, mean +/- s.e.m.), while developing progressive DE and hyperthermia (3.9 +/- 0.3 % body weight loss and 39.7 +/- 0.2 C oesophageal temperature, Toes). On the second trial (control), they cycled for the same period of time maintaining euhydration by ingesting fluids and stabilising Toes at 38.2 +/- 0.1 degrees C. 3. After 20 min of exercise in both trials, leg blood flow (LBF) and leg exchange of lactate, glucose, free fatty acids (FFA) and glycerol were similar. During the 20 to 135 +/- 4 min period of exercise, LBF declined significantly in DE but tended to increase in control. Therefore, after 120 and 135 +/- 4 min of DE, LBF was 0.6 +/- 0.2 and 1.0 +/- 0.3 l min-1 lower (P < 0.05), respectively, compared with control. 4. The lower LBF after 2 h in DE did not alter glucose or FFA delivery compared with control. However, DE resulted in lower (P < 0.05) net FFA uptake and higher (P < 0.05) muscle glycogen utilisation (45 %), muscle lactate accumulation (4.6-fold) and net lactate release (52 %), without altering net glycerol release or net glucose uptake. 5. In both trials, the mean convective heat transfer from the exercising legs to the body core ranged from 6.3 +/- 1.7 to 7.2 +/- 1.3 kJ min-1, thereby accounting for 35-40 % of the estimated rate of heat production ( approximately 18 kJ min-1). 6. At exhaustion in DE, blood lactate values were low whereas blood glucose and muscle glycogen levels were still high. Exhaustion coincided with high body temperature ( approximately 40 C). 7. In conclusion, the present results demonstrate that reductions in exercising muscle blood flow with dehydration do not impair either the delivery of glucose and FFA or the removal of lactate during moderately intense prolonged exercise in the heat. However, dehydration during exercise in the heat elevates carbohydrate oxidation and lactate production. A major finding is that more than one-half of the metabolic heat liberated in the contracting leg muscles is dissipated directly to the surrounding environment. The present results indicate that hyperthermia, rather than altered metabolism, is the main factor underlying the early fatigue with dehydration during prolonged exercise in the heat.

Effetti della somministrazione di Testosterone in donne

Come noto, il testosterone (T) gioca un ruolo importante in differenti funzioni fisiologiche. Il ruolo del T nelle donne è tuttavia largamente sconosciuto. Recenti studi riportano un ruolo del T nella modulazione della funzionalità sessuale femminile. SCOPO: Indagare gli effetti del T nelle donne, su parametri metabolici, ossei e composizione corporea e studiare gli effetti del T sulla proliferazione e innervazione della vagina. METODI: 16 soggetti FtM ovariectomizzati sono stati sottoposti a terapia con TU 1000 mg im + placebo o dutasteride. Alla settimana 0 e 54 sono stati valutati: parametri metabolici e composizione corporea. 16 campioni di tessuto vaginale ottenuti da soggetti FtM trattati con T, 16 donne PrM e 16 donne M sono stati analizzati. Sono stati valutati: morfologia, contenuto di glicogeno, espressione del Ki-67, recettori per estrogeni e androgeni ed innervazione. RISULTATI: La somministrazione di T in soggetti FtM determina aumento del colesterolo LDL e riduzione delle HDL. L’HOMA si riduce significativamente nel gruppo TU e tende ad aumentare nel gruppo TU+D. L’ematocrito aumenta. BMI, WHR e grasso tendono a ridursi, la massa magra ad aumentare. Non riportiamo cambiamenti del metabolismo osseo. Nel tessuto vaginale di FtM osserviamo perdita della normale architettura dell’epitelio. La somministrazione di T determina riduzione della proliferazione cellulare. I recettori per E e il PGP 9.5 sono significativamente ridotti nei FtM. La presenza di recettori per A è dimostrata nello stroma e nell’epitelio. L’espressione di AR si riduce con l’età e non cambia con la terapia con T nella mucosa, mentre aumenta nello stroma dopo somministrazione di T. CONCLUSIONI: Non riportiamo effetti avversi maggiori dopo somministrazione di T. La terapia con T determina ridotta proliferazione dell’epitelio vaginale. I recettori per AR sono presenti sia nello stroma che nell’epitelio. T aumenta l’espressione di AR nello stroma.

Relationship between aetiology and left ventricular systolic dysfunction in hypertrophic cardiomyopathy

Background: Hypertrophic cardiomyopathy (HCM) is a common cardiac disease caused by a range of genetic and acquired disorders. The most common cause is genetic variation in sarcomeric proteins genes. Current ESC guidelines suggest that particular clinical features (‘red flags’) assist in differential diagnosis. Aims: To test the hypothesis that left ventricular (LV) systolic dysfunction in the presence of increased wall thickness is an age-specific ‘red flag’ for aetiological diagnosis and to determine long-term outcomes in adult patients with various types of HCM. Methods: A cohort of 1697 adult patients with HCM followed at two European referral centres were studied. Aetiological diagnosis was based on clinical examination, cardiac imaging and targeted genetic and biochemical testing. Main outcomes were: all-cause mortality or heart transplantation (HTx) and heart failure (HF) related-death. All-cause mortality included sudden cardiac death or equivalents, HF and stroke-related death and non-cardiovascular death. Results: Prevalence of different aetiologies was as follows: sarcomeric HCM 1288 (76%); AL amyloidosis 115 (7%), hereditary TTR amyloidosis 86 (5%), Anderson-Fabry disease 85 (5%), wild-type TTR amyloidosis 48 (3%), Noonan syndrome 15 (0.9%), mitochondrial disease 23 (1%), Friedreich’s ataxia 11 (0.6%), glycogen storage disease 16 (0.9%), LEOPARD syndrome 7 (0.4%), FHL1 2 (0.1%) and CPT II deficiency 1 (0.1%). Systolic dysfunction at first evaluation was significantly more frequent in phenocopies than sarcomeric HCM [105/409 (26%) versus 40/1288 (3%), (p<0.0001)]. All-cause mortality/HTx and HF-related death were higher in phenocopies compared to sarcomeric HCM (p<0.001, respectively). When considering specific aetiologies, all-cause mortality and HF-related death were higher in cardiac amyloidosis (p<0.001, respectively). Conclusion: Systolic dysfunction at first evaluation is more common in phenocopies compared to sarcomeric HCM representing an age-specific ‘red flag’ for differential diagnosis. Long-term prognosis was more severe in phenocopies compared to sarcomeric HCM and when comparing specific aetiologies, cardiac amyloidosis showed the worse outcomes.