Physiological profile regulation during weight gain and loss by ovariectomized females: importance of SIRT1 and SIRT4.

Obesity in menopausal women occurs because of the systemic effects of loss of ovarian function, resulting in increased body weight and oxidative stress. Caloric restriction (CR) is essential for weight loss, since it provides benefits associated with metabolic normalization resulting from the action of sirtuins. The aim of this work was to evaluate the physiological effects of weight cycling in ovariectomized females. Females aged 2 mo (n = 8/group) were submitted to simulated surgery, ovariectomy (OVX group), and ovariectomy with weight fluctuation (WF group). In the WF group, weight cycling was performed two times, using 21 days of ad libitum commercial feed and 21 days of caloric restriction with 40% of the feed consumed by the OVX group. After 17 wk, the animals were evaluated experimentally. Weight fluctuations reduced triacylglycerol and the adipose tissue index of the WF animals, while increasing the expression of antioxidant proteins. In addition to causing fluctuations in the physiological parameters, the weight cycling led to increases of adipocyte number and serum fatty acids. These effects were reflected in increased expression of the sirtuin (SIRT) 1 and SIRT4 proteins, as well as protein complexes of the mitochondrial electron transport chain, especially in the liver and adipose tissues. The weight-cycling results suggested that mitochondrial and nuclear sirtuins were active in cellular signaling for the control of lipid metabolism, oxidative phosphorylation, and redox status. Weight cycling was able to restore the health characteristics of lean animals.

Tissue-specific transcriptional regulation of epithelial/endothelial and mesenchymal markers during renovascular hypertension.

Epithelial-to-mesenchymal transition (EMT) and endothelial-to-mesenchymal transition are processes that can occur under different biological conditions, including tissue healing due to hypertension and oxidative stress. The purpose of the present study was to evaluate the differences in gene expression of epithelial/endothelial and mesenchymal markers in different tissues. A two-kidney, one-clip (2K1C) renovascular hypertension rat model was used. Hypertension was induced by the clipping of the left renal artery; the rats were randomized into sham and 2K1C groups and monitored for up to 4 weeks. The gene expressions of E-cadherin (E-cad), N-cadherin (N-cad), α-smooth muscle actin (α-SMA), collagen I (COL1A1), collagen III (COL3A1) and hepatocyte growth factor (HGF) were determined by reverse transcription-PCR. The levels of the cytokines transforming growth factor-ß1, tumor necrosis factor-α, interleukin (IL)-4, IL-6 and IL-10 were evaluated using ELISAs. The levels of thiobarbituric acid reactive substances and thiol groups were measured to evaluate oxidative stress. All analyses were performed on the liver, heart and kidneys tissues of sham and model rats. The 2K1C animals exhibited a higher systolic blood pressure, as well as cardiac hypertrophy and atrophy of the left kidney. Fibrotic alterations in the heart and kidneys were observed, as was an increase in the collagen fiber areas, and higher levels of inflammatory cytokines, which are associated with the increased expression of fibroproliferative and anti-fibrotic genes. Renovascular hypertension regulated epithelial/endothelial and mesenchymal markers, including E-cad, N-cad, α-SMA and COL1A1 in the kidneys and heart. EMT in the kidneys was mediated by an increased level of inflammatory and profibrotic cytokines, as well as by oxidative stress. The data in the present study suggested that the expression of epithelial/endothelial and mesenchymal markers are differentially regulated by hypertension in the liver, heart and kidneys.

Mechanistic insights into functional characteristics of native crotamine.

The chemical composition of snake venoms is a complex mixture of proteins and peptides that can be pharmacologically active. Crotamine, a cell-penetrating peptide, has been described to have antimicrobial properties and it exerts its effects by interacting selectively with different structures, inducing changes in the ion flow pattern and cellular responses. However, its real therapeutic potential is not yet fully known. Bearing in mind that crotamine is a promising molecule in therapeutics, this study investigated the action of purified molecule in three aspects: I) antibacterial action on different species of clinical interest, II) the effect of two different concentrations of the molecule on platelet aggregation, and III) its effects on isolated mitochondria. Crotamine was purified to homogeneity in a single step procedure using Heparin Sepharose. The molecular mass of the purified enzyme was 4881.4 Da, as determined by mass spectrometry. To assess antibacterial action, changes in the parameters of bacterial oxidative stress were determined. The peptide showed antibacterial activity on Escherichia coli (MIC: 2.0 µg/µL), Staphylococcus aureus (MIC: 8-16 µg/µL) and methicillin-resistant Staphylococcus aureus (MIC: 4.0-8.0 µg/µL), inducing bacterial death by lipid peroxidation and oxidation of target proteins, determined by thiobarbituric acid reactive substances and sulfhydryl groups, respectively. Crotamine induced increased platelet aggregation (IPA) at the two concentrations analyzed (0.1 and 1.4 µg/µL) compared to ADP-induced aggregation of PRP. Mitochondrial respiratory parameters and organelle structure assays were used to elucidate the action of the compound in this organelle. The exposure of mitochondria to crotamine caused a decrease in oxidative phosphorylation and changes in mitochondrial permeability, without causing damage in the mitochondrial redox state. Together, these results support the hypothesis that, besides the antimicrobial potential, crotamine acts on different molecular targets, inducing platelet aggregation and mitochondrial dysfunction.

Release of NO by a nitrosyl complex upon activation by the mitochondrial reducing power.

The reaction of trans-[Ru(NH(3))(4)P(OEt)(3)NO](3+) and mitochondria was investigated through differential pulse polarography and fluorimetry. The nitrosyl complex undergoes one-electron reduction centered on the NO ligand site. The reaction between the mitochondrial reductor and trans-[Ru(NH(3))(4)P(OEt)(3)NO](3+) exhibits a second order specific rate constant calculated as k=2 x 10(1) M(-1) s(-1). The reduced species, trans-[Ru(NH(3))(4)P(OEt)(3)NO](2+), quickly releases NO, yielding trans-[Ru(NH(3))(4)P(OEt)(3)H(2)O](2+). The low toxicities of both trans-[Ru(NH(3))(4)P(OEt)(3)(NO)](2+) and trans-[Ru(NH(3))(4)P(OEt)(3)H(2)O](2+) and its ability to release NO after reductive activation in a biological medium make the nitrosyl compound a useful model of a hypotensive drug.

Anti-hemorrhagic effect of hydro-alcoholic extract of the leaves of Mikania glomerata in lesions induced by Bothrops jararaca venom in rats.

PURPOSE: To investigate the effects of hydroalcoholic leaf extract of Mikania glomerata Spreng (Asteraceae) on the activity of Bothrops jararaca snake venom in Wistar rats. METHODS: Fifty four rats Wistar were divided into six groups of nine animals in each: control treated with saline; control treated with B. jararaca venom; control treated with M. glomerata extract; B. jararaca venom incubated with M. glomerata extract at proportions of 1:1, 1:2, and 1:4. RESULTS: Histopathological and morphometric analysis showed that intradermal administration of snake venom incubated with the hydroalcoholic extract at proportions of 1:1, 1:2 and 1:4 promoted a significant reduction in the number of inflammatory cells and a marked decrease in edema after the third hour. There was also a significant reduction in the intensity of the hemorrhagic halo in animals receiving the snake venom incubated with the extract, with the observation of a progressive and parallel inhibition with increasing proportion of M. glomerata. CONCLUSION: The Mikania glomerata hydroalcoholic extract exerted effective anti-inflammatory and antihemorrhagic activity against the effects induced by Bothrops jararaca snake venom.

Anti-hemorrhagic effect of hydro-alcoholic extract of the leaves of Mikania glomerata in lesions induced by Bothrops jararaca venom in rats

To investigate the effects of hydroalcoholic leaf extract of Mikania glomerata Spreng (Asteraceae) on the activity of Bothrops jararaca snake venom in Wistar rats. METHODS: Fifty four rats Wistar were divided into six groups of nine animals in each: control treated with saline; control treated with B. jararaca venom; control treated with M. glomerata extract; B. jararaca venom incubated with M. glomerata extract at proportions of 1:1, 1:2, and 1:4. RESULTS: Histopathological and morphometric analysis showed that intradermal administration of snake venom incubated with the hydroalcoholic extract at proportions of 1:1, 1:2 and 1:4 promoted a significant reduction in the number of inflammatory cells and a marked decrease in edema after the third hour. There was also a significant reduction in the intensity of the hemorrhagic halo in animals receiving the snake venom incubated with the extract, with the observation of a progressive and parallel inhibition with increasing proportion of M. glomerata. CONCLUSION: The Mikania glomerata hydroalcoholic extract exerted effective anti-inflammatory and antihemorrhagic activity against the effects induced by Bothrops jararaca snake venom.

Adequacies of skin puncture for evaluating biochemical and hematological blood parameters in athletes.

OBJECTIVE: The authors tested the effect of blood sampling (skin versus venous puncture) on some biochemical and hematological blood parameters in athletes to answer whether skin puncture could be used as a substitute for venous puncture. DESIGN: Comparative study of 2 methods of blood samples collection. SETTING: The blood was collected in the same athletes at 3 different moments of the preparatory training phase. PARTICIPANTS: Fourteen male indoor soccer players (22 +/- 1 years old) and 7 female handball players (18 +/- 1 years old) participated. MAIN OUTCOME MEASUREMENT: Blood was collected in heparin and K3EDTA by Vacutainer BD or Microvette Sarstedt system for biochemical and hematological analyses, respectively. RESULTS: There were no significant statistical differences between the 2 methods for the values of creatine kinase, urea, creatinine, lymphocytes, and platelets. The other hematological analyzes and uric acid exhibited significant higher values in skin blood, although they were all within the normal expected range. A high degree of correlation was observed between the 2 techniques for all parameters. CONCLUSIONS: Skin puncture is a reliable, easy, accurate, and less invasive sampling method for assessing hematological and some biochemical parameters in athletes, respecting that blood samples should always be obtained from the same site, especially in follow-up studies.

Absolute quantification of gene E7 in cervical samples of women infected by HPV using real time PCR

Objective: High grade oncogenic types of human papillomavirus (HPV), especially HPV16 and HPV18, possess a gene called E7, which acts on genes that regulate cell growth, promoting development of pre-neoplastic lesions that can lead to invasive carcinomas. The absolute quantification of this gene in cervical samples of HPV-infected women may contribute for better understanding the evolution of these lesions induced by the virus. Methods: We collected 60 cervicovaginal smears of women infected by HPV with or without uterine cervical squamous intraepithelial lesion, SIL) and 10 samples of women with no HPV infection or SIL. The absolute quantification of gene E7 was performed by Realtime PCR using specific primers and probes. Results: Samples infected by HPV16 have a higher number of gene E7 copies when compared to samples infected by HPV18. In the HPV18 group it was observed that those obtained from patients with low or high grade squamous intraepithelial lesions (HSIL) or invasive cervical cancer presented significantly higher concentrations of gene E7 when compared to patients with no cervical lesions. The number of gene E7 copies was higher in the group infected by HPV16 than by HPV18. In spite of that, there was no difference in the number of gene E7 copies in samples infected by HPV16 with or without SIL. Conclusions: Among the samples with HPV18, the number of copies of gene E7 was higher in the group with cervical lesions, and no differences were found for SIL, HSIL or invasive cancer patients.

Efeito da lipólise induzida pela cafeína na performance e no metabolismo de glicose durante o exercício intermitente / Effect of incresed caffeine-induced lipolysis on performance and glucose metabolism during intermittent exercise

Uma elevada taxa na oxidação de ácidos graxos reduz a oxidação de glicose em músculo esquelético. Esse efeito seria importante durante o exercício intermitente intenso, uma vez que, baixos níveis de glicogênio ou altos níveis de lactato muscular estão diretamente envolvidos com o mecanismo de fadiga muscular. Nosso objetivo foi examinar se uma maior disponibilidade de ácidos graxos induz uma redução nos níveis de lactato e glicose sanguínea, seguido de um aumento no tempo de exaustão (TE) durante o exercício intermitente intenso. 10 ciclistas masculinos foram submetidos a testes para determinação do limiar anaeróbio (LA), potência anaeróbia máxima (P.A.M.) e índice de fadiga (I.F.). Após 48 h, foram submetidos a uma sessão de exercício intermitente no ciclo-ergômetro a uma intensidade de 30% acima do LA. Os participantes ingeriram cafeína (CF) (5 mg.kg-1) ou placebo (PL) (5 mg.kg-1) 60 min antes do exercício. Amostras de sangue para determinação de cafeína e ácidos graxos livres (AGL) foram coletadas antes do exercício (0 min) e para determinação de glicose e lactato foram coletadas a cada 5 min durante o exercício. Entre as diferentes variáveis coletadas houve uma diferença significativa no tempo de exaustão (TE) após a ingestão de CF comparado a mesma situação após ingesta de PL (82,4 ± 28 vs 56,2 ± 17 min) (p < 0,05). A ingesta de CF também aumentou as concentrações de AGL antes de exercício (0,183 ± 0,097 vs 0,110 ± 0,052 g.dL-1) (p < 0,05). As concentrações de glicose sanguínea aumentaram significantemente com CF apenas nos instantes finais do exercício (p < 0,05), ao passo que as concentrações de lactato não sofreram alterações (p > 0,05). Os valores de percepção subjetiva de esforço (PSE) foram estatisiticamente significativos apenas no final do exercício quando as análises foram realizadas dentro de cada grupo isoladamente (p < 0,05).

This study examined the influence of caffeine on changes in selected blood and performance variables in response to intermittent exercise. 10 male cyclists withdrew all dietary sources of caffeine for 72 h before two tests. One hour before exercise they ingested placebo (PL) or caffeine (CF) capsules (5 mg.kg-1), rested quietly and then cycled at 30% above the anaerobic threshold (AT) until voluntary exhaustion. Blood samples for caffeine and free fatty acids (FFA) analysis were taken immediately before the exercise and samples for glucose and lactate analysis were taken during exercise. The variables rating perceived exertion (RPE), heart rate (HR) and time to exhaustion (TE) were also measured during exercise. There was a significant difference in CF compared with PL trial for TE (82,4 ± 28 vs 56,2 ± 17 min) and FFA (0,183 ± 0,097 vs 0,110 ± 0,052 g.dL-1) (p < 0,05). Glucose blood concentrations also significantly increased in CF trial in the end of exercise (p < 0,05), whereas lactate concentrations did not change during the exercise for both trial (p > 0,05). The RPE values just show significance toward the end of exercise when the result were compared separately into the same group (p < 0,05), but failed for significance when CF and PL were compared (p > 0,05). Therefore, our results suggest that an increased caffeine-induced lipolysis may contributed with a reduced consume of glucose by skeletal muscle following by a marked increase in the performance during intermittent exercise.

Efeito da aplicação de microcorrente na osteogênese após a fratura / The use of microcurrent on the osteogenesis after fracture

A produção de potenciais elétricos em tecidos biológicos como osso, dentina e outros, é obtida aplicando-se forças mecânicas sobre os mesmos. Este fenômeno conhecido como piezoeletricidade, desempenha papel importante na bioestimulação do processo de reparo de diferentes tecidos, isto porque correntes elétricas afetam a atividade celular e, assim, induzem o crescimento do osso e a osteogênese. No presente estudo investigou-se o efeito de diferentes intensidades de microcorrente no processo da osteogênese na tíbia de ratos da linhagem Wistar após fraturas cirúrgicas. Os animais foram dividos em quatro grupos de controle e submetidos a tratamento diário com microcorrente, com intensidade de 2µA/3min, 2µA/5min e 5µA/3min durante 28 dias. Os resultados mostraram que a estimulação diária com 5µA/3min foi efetiva no aumento da velocidade de reparo ósseo