Exercise and spirulina control non-alcoholic hepatic steatosis and lipid profile in diabetic Wistar rats

<p>Abstract</p> <p>Background</p> <p>Diabetes mellitus is associated with metabolic dysfunctions, including alterations in circulating lipid levels and fat tissue accumulation, which causes, among other pathologies, non-alcoholic fatty liver disease (NAFLD).</p> <p>Aim of the study</p> <p>The objective of this study was to analyse the effects of physical exercise and <it>spirulina </it>intake on the control of NAFLD in diabetic Wistar rats.</p> <p>Methods</p> <p>Diabetes was induced in the animals through intravenous administration of alloxan. The rats were divided into four groups: Diabetic Control (DC) - diabetic rats fed with a control diet and no physical exercise; Diabetic <it>Spirulina </it>(DS) - diabetic rats fed with a diet that included <it>spirulina</it>; Diabetic <it>Spirulina </it>and Exercise (DSE) - diabetic rats fed with a diet that included <it>Spirulina </it>and that exercised; and Diabetic Exercise (DE) - diabetic rats fed with a control diet and that exercised.</p> <p>Results</p> <p>The groups DS, DSE, and DE presented lower plasma concentrations of LDL cholesterol than DC, as well as lower levels of total liver lipids in groups DS, DSE, and DE in comparison to DC.</p> <p>Conclusion</p> <p>Thus, <it>spirulina </it>appears to be effective in reducing total circulating levels of LDL-cholesterol and hepatic lipids, alone or in conjunction with physical exercise in diabetic rats.</p

Dietary restriction, caloric value and the accumulation of hepatic fat

<p>Abstract</p> <p>Background</p> <p>Studies using laboratory animals under what are considered to be "standard" conditions normally offer unrestricted amounts of food to the animals, which can lead to metabolic disorders. Moreover, standard diets have different compositions.</p> <p>Aim</p> <p>Therefore, the aim of the present study was to assess the effects of two non-isocaloric diets (commercial Purina^®and AIN-93M), which are considered standard diets, on the accumulation of fat in the liver of rats when offered ad libitum or in a restricted amount.</p> <p>Methods</p> <p>Thus, 40 Wistar rats (90 days old) were separated into 4 groups according to the amount of food offered (ad libitum or dietary restriction) and the type of diet (commercial diet, 3,028.0 kcal/g or AIN-93M, 3,802.7 kcal/g): animals fed the commercial Purina^®diet ad libitum (AP), animals fed restricted amounts of the commercial Purina^®diet (RP), animals fed the AIN-93M diet ad libitum (AD), and animals fed restricted amounts of the AIN-93M diet (RD). Dietary restriction consisted of pair-feeding the RP and RD groups with 60% of the total food consumed by the corresponding ad libitum groups.</p> <p>Results</p> <p>Because of its higher carbohydrate and calorie content, AIN-93M was found to accelerate weight gain, reduce glucose tolerance and peripheral insulin sensitivity, and increase the amount of fat in the liver when compared to the commercial diet. Conversely, a 40% dietary restriction assisted in weight loss without causing malnutrition, contributing to an improved glucose tolerance and higher levels of HDL cholesterol.</p> <p>Conclusion</p> <p>Therefore, differences in the amount of carbohydrates and calories provided by the diet can lead to important metabolic disorders, such as impaired tolerance and accumulation of hepatic fat, and dietary restriction improves serum and tissue lipid profiles in laboratory animals.</p

Exercise counteracts fatty liver disease in rats fed on fructose-rich diet

<p>Abstract</p> <p>Background</p> <p>This study aimed to analyze the effects of exercise at the aerobic/anaerobic transition on the markers of non-alcoholic fatty liver disease (NAFLD), insulin sensitivity and the blood chemistry of rats kept on a fructose-rich diet.</p> <p>Methods</p> <p>We separated 48 Wistar rats into two groups according to diet: a control group (balanced diet AIN-93 G) and a fructose-rich diet group (60% fructose). The animals were tested for maximal lactate-steady state (MLSS) in order to identify the aerobic/anaerobic metabolic transition during swimming exercises at 28 and 90 days of age. One third of the animals of each group were submitted to swimming training at an intensity equivalent to the individual MLSS for 1 hours/day, 5 days/week from 28 to 120 days (early protocol). Another third were submitted to the training from 90 to 120 days (late protocol), and the others remained sedentary. The main assays performed included an insulin tolerance test (ITT) and tests of serum alanine aminotransferase [ALT] and aspartate aminotransferase [AST] activities, serum triglyceride concentrations [TG] and liver total lipid concentrations.</p> <p>Results</p> <p>The fructose-fed rats showed decreased insulin sensitivity, and the late-exercise training protocol counteracted this alteration. There was no difference between the groups in levels of serum ALT, whereas AST and liver lipids increased in the fructose-fed sedentary group when compared with the other groups. Serum triglycerides concentrations were higher in the fructose-fed trained groups when compared with the corresponding control group.</p> <p>Conclusions</p> <p>The late-training protocol was effective in restoring insulin sensitivity to acceptable standards. Considering the markers here evaluated, both training protocols were successful in preventing the emergence of non-alcoholic fatty liver status disease.</p

Long-term effects of moderate physical exercise during early childhood on insulin sensitivity in rats during adulthood

It is of great importance to investigate the effects of physical exercise for metabolic health when performed in early life, and what the adulthood response would be. The aim of this study is to analyse the effects of moderate intensity physical exercise protocol during childhood on the adipose tissue and insulin sensitivity of rats during adulthood. Twenty weaned Wistar (28 days old) were divided into control and trained groups. The Control Group was kept sedentary, and the Trained group was submitted to swimming exercise at 80% of the anaerobic threshold (determined by the lactate minimum test) for 1 hour/day, 5 days/week from 28 to 90 days of age. At the end of the experiment, the body weight, adiposity (adipose tissue weight), insulin sensitivity, glycemia, insulinemia, pancreatic insulin, lipogenic activity in mesenteric fat, lipogenic activity and glycogen store in gastrocnemius and glucose uptake by soleus were analyzed. Trained group showed lower body weight gain, fat acumulation, lipid synthesis, glycemia, insulinemia and pancreatic insulin level. Kitt, HOMA-IR, glycogen store in gastrocnemius and glucose uptake by soleus were higher in this group. Therefore, we conclude that the moderate physical exercise performed during childhood can contribute to the reduction of body fat and insulin resistance during adulthood in Wistar rats.É de grande importância a investigação dos efeitos do exercício para a saúde metabólica quando realizado no início da vida, e quais seriam as respostas durante a fase adulta. O objetivo desse estudo é analisar os efeitos do exercício físico de intensidade moderada durante a infância na adiposidade e sensibilidade à insulina de ratos durante a fase adulta. Vinte ratos Wistar desmamados de 28 dias de vida foram divididos em grupos Controle e Treinado. O grupo Controle permaneceu sedentário, enquanto o grupo Treinado realizou exercício de natação a 80% do limiar anaeróbio (determinado pelo teste de lactato mínimo) por 1hora/dia, 5dias/semana do 28º até o 90º dia de vida. No fim do experimento, a massa corporal, adiposidade, sensibilidade à insulina, glicemia, insulinemia, insulina pancreática, atividade lipogênica do tecido adiposo mesentérico, atividade lipogênica e estoques de glicogênio no músculo gastrocnêmio e captação de glicose pelo músculo sóleo foram analizadas. O grupo Treinado apresentou menor ganho de massa corporal, acúmulo de gordura, síntese de lipídios, glicemia, insulinemia e insulina pancreática. Kitt, HOMA-IR, estoques de glicogênio no gastrocnêmio e captação de glicose pelo sóleo foram maiores nesse grupo. Portanto, concluímos que o exercício físico moderado realizado durante a infância pode contribuir para a redução da adiposidade corporal e resistência à insulina durante a fase adulta em ratos Wistar

HISTÓRICO DA COMPOSIÇÃO DA VEGETAÇÃO ARBÓREA DO PARQUE DO IBIRAPUERA E SUA CONTRIBUIÇÃO PARA A CONSERVAÇÃO DA BIODIVERSIDADE

Os parques urbanos, além de importantes espaços de recreação, esportes, lazer, cultura e promover melhoria na qualidade de vida, apresentam potencial de contribuir para a biodiversidade regional. Objetivou-se discutir as modificações históricas da composição da vegetação arbórea do Parque Ibirapuera de São Paulo, SP; sua contribuição para a conservação da biodiversidade regional; e analisar as espécies arbóreas do Parque quanto ao risco de queda. Para isso, foi elaborado inventário por censo dos indivíduos arbóreos do Parque Ibirapuera. Historicamente as primeiras vegetações inseridas no Parque possuíam o papel de promover a drenagem da área com o uso de espécies arbóreas exóticas, como as do gênero Eucalyptus e Ligustrum, que hoje representam 16% e 7,29% das árvores, respectivamente. Estas representaram a maior porcentagem de espécies classificadas em risco de queda alto, 83,7%. A inserção posterior de espécies nativas no Parque contribuiu para o aumento da biodiversidade regional, atualmente apresentando 39,4% de árvores nativas brasileiras. Os resultados indicam a necessidade da contínua diversificação de árvores e arbustos com espécies nativas, pois além de contribuir para a minimização de pragas e doenças vegetais, pela manutenção da diversidade e dos processos ecológicos na paisagem urbana, poderá prevenir fatores importantes que provocam a queda de árvores

Muscle protein metabolism in neonatal alloxan-administered rats: effects of continuous and intermittent swimming training

<p>Abstract</p> <p>Background</p> <p>This study aimed to examine the effects of intermittent and continuous swimming training on muscle protein metabolism in neonatal alloxan-administered rats.</p> <p>Methods</p> <p>Wistar rats were used and divided into six groups: sedentary alloxan (SA), sedentary control (SC), continuous trained alloxan (CA), intermittent trained alloxan (IA), continuous trained control (CC) and intermittent trained control (IC). Alloxan (250 mg/kg body weight) was injected into newborn rats at 6 days of age. The continuous training protocol consisted of 12 weeks of swimming training in individual cylinder tanks while supporting a load that was 5% of body weight; uninterrupted swimming for 1 h/day, five days a week. The intermittent training protocol consisted of 12 weeks of swimming training in individual cylinder tanks while supporting a load that was 15% of body weight; 30 s of activity interrupted by 30 s of rest for a total of 20 min/day, five days a week.</p> <p>Results</p> <p>At 28 days, the alloxan animals displayed higher glycemia after glucose overload than the control animals. No differences in insulinemia among the groups were detected. At 120 days, no differences in serum albumin and total protein among the groups were observed. Compared to the other groups, DNA concentrations were higher in the alloxan animals that were subjected to continuous training, whereas the DNA/protein ratio was higher in the alloxan animals that were subjected to intermittent training.</p> <p>Conclusion</p> <p>It was concluded that continuous and intermittent training sessions were effective in altering muscle growth by hyperplasia and hypertrophy, respectively, in alloxan-administered animals.</p

Expression of the Inherently Autoreactive Idiotope 9G4 on Autoantibodies to Citrullinated Peptides and on Rheumatoid Factors in Patients with Early and Established Rheumatoid Arthritis.

The pre-symptomatic stage of Rheumatoid arthritis (RA) is associated with pro-inflammatory cytokines and autoantibodies. High levels and epitope spread by Rheumatoid factors (RhF) and autoantibodies to citrullinated proteins signify progression towards disease expression. In established RA, the persistence of high autoantibody levels reflects production by both long-lived plasma cells and short-lived plasmablasts. Neither the relative contributions to pathogenesis by autoantibodies from either source, nor the factors responsible for deciding the fate of autoantigen specific 'parent' B-cells, is understood. Phenotypic markers identifying subsets of autoreactive B-cells are therefore of interest in understanding the origin and perpetuation of the autoimmune response in RA. One such phenotypic marker is the rat monoclonal antibody, 9G4, which recognises an idiotope on immunoglobuins derived from the inherently autoreactive VH-gene, VH4-34. We therefore investigated whether the 9G4 idiotope was expressed on autoantibodies in patients with RA

Integrated terrestrial-freshwater planning doubles conservation of tropical aquatic species

Conservation initiatives overwhelmingly focus on terrestrial biodiversity, and little is known about the freshwater cobenefits of terrestrial conservation actions. We sampled more than 1500 terrestrial and freshwater species in the Amazon and simulated conservation for species from both realms. Prioritizations based on terrestrial species yielded on average just 22% of the freshwater benefits achieved through freshwater-focused conservation. However, by using integrated cross-realm planning, freshwater benefits could be increased by up to 600% for a 1% reduction in terrestrial benefits. Where freshwater biodiversity data are unavailable but aquatic connectivity is accounted for, freshwater benefits could still be doubled for negligible losses of terrestrial coverage. Conservation actions are urgently needed to improve the status of freshwater species globally. Our results suggest that such gains can be achieved without compromising terrestrial conservation goals