Postprandial thermogenesis in Bothrops moojeni (Serpentes: Viperidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The contribution of air breathing to aerobic scope and exercise performance in the banded knifefish Gymnotus carapo L.

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The unequal influences of the left and right vagi on the control of the heart and pulmonary artery in the rattlesnake, Crotalus durissus

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Thermoregulation by an Australian murine rodent, the ash-grey mouse (Pseudomys albocinereus)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Controle do fornecimento e da utilização de substratos energéticos no encéfalo

Correspondendo a apenas 2% do peso corpóreo, o cérebro apresenta taxa metabólica superior à maioria dos demais órgãos e sistemas. A maior parte do consumo energético encefálico ocorre no transporte iônico para manutenção do potencial de membrana celular. Praticamente desprovido de estoques, os substratos energéticos para o encéfalo são fornecidos necessariamente pela circulação sanguínea.O suprimento desses substratos sofre também a ação seletiva da barreira hemato-encefálica (BHE). O principal substrato, que é a glicose, tem uma demanda de 150 g/dia (0,7 mM/g/min). A metabolização intracelular parece ser controlada pela fosfofrutoquinase. A manose e os produtos intermediários do metabolismo (frutose 1,6 bifosfato, piruvato, lactato e acetato) podem substituir, em parte, a glicose, quando os níveis sangüíneos desta encontram-se elevados. Quando oxidado, o lactato chega a responder por 21% do consumo cerebral de Ov em situações de isquemia e inflamação infecciosa, o tecido cerebral passa de consumidor a produtor de lactato. Os corpos cetônicos também podem reduzir as necessidades cerebrais de glicose desde que oferecidos em quantidades suficientes ao encéfalo. Entretanto, devem ser considerados como um substrato complementar e nunca alternativo da glicose, pois comprometem a produção cerebral de succinil CoA e GTP. Quanto aos demais substratos, embora apresentem condições metabólicas, não existem demonstrações consistentes de que o cérebro produza energia a partir dos ácidos graxos sistêmicos, mesmo em situações de hipoglicemia. de maneira análoga, etanol e glicerol são considerados apenas a nível de experimentação. A utilização dos aminoácidos é dependente da sua captação, limitada tanto pela baixa concentração sangüínea, como pela seletividade da BHE. A maior captação ocorre para os de cadeia ramificada e destes, a valina. A menor captação é a de aminoácidos sintetizados no cérebro (aspartato,gluconato e alanina). Todos podem ser oxidados a CO, e H(2)0. Entretanto, mesmo com o consumo de glicose reduzido a 50%, a contribuição energética dos aminoácidos não ultrapassa 10%. Para manter o suprimento adequado de glicose e oxigênio, o fluxo sangüíneo cerebral é da ordem de 800 ml/min (15% do débito cardíaco). O consumo de O, pelo cérebro é equivalente a 20% do total consumido pelo corpo. Esses mecanismos, descritos como controladores da utilização de substratos energéticos pelo cérebro, sofrem a influência da idade apenas no período perinatal, com a oxidação do lactato na fase pré-latente e dos corpos cetônicos, no início da amamentação.

Utilização das recomendações de nutrientes para estimar prevalência de consumo insuficiente das vitaminas C e E em gestantes

Na gestação ocorrem adaptações que conduzem a um aumento da taxa metabólica basal, caracterizando um estado de alto nível de estresse oxidativo, tornando relevante a avaliação do consumo de nutrientes antioxidantes por mulheres grávidas. Este estudo teve como objetivo estimar a prevalência de consumo insuficiente das vitaminas C e E em gestantes assistidas em serviços públicos de saúde. Estudou-se amostra (n=107) representativa das mulheres no segundo trimestre gestacional atendidas durante o pré-natal nas unidades de atenção básica do município de Botucatu/SP. O consumo foi investigado mediante dois inquéritos recordatórios de 24 horas. Para estimar a prevalência de inadequação de consumo na população, foi utilizado o método EAR como ponto de corte. Diferenças de consumo (em tercis) em relação a fatores socioeconômicos, obstétricos e hábitos de vida foram pesquisadas mediante análise estratificada, adotando-se p<0.05 como nível de significância. As prevalências estimadas de consumo insuficiente das vitaminas C e E foram 60% e 91,5%, respectivamente. Houve associação inversa entre o consumo de vitamina E com paridade e o consumo de vitamina C foi menor nas adolescentes em relação às adultas. Estes resultados indicam a necessidade de intervenções individuais e coletivas de promoção e apoio ao consumo de alimentação saudável por mulheres em idade fértil. Conclui-se que a prevalência de inadequação do consumo das vitaminas C e E é elevada e sem contrastes socioeconômicos.

ONTOGENIC VARIATION OF OXYGEN-UPTAKE IN THE PITVIPER BOTHROPS MOOJENI (SERPENTES, VIPERIDAE)

The scaling of oxygen uptake was measured along the ontogeny, in the neotropical pitviper Bothrops moojeni. Allometric relationship between oxygen uptake and body mass, quantified for juveniles, sub-adults and adults, showed the same mass coefficient and exponent. The uniformity of mass constants along ontogeny suggests that B. moojeni is energetically homomorphic. Variation in mass seem to be the sole determinant of oxygen uptake, and structural modifications have no effect on the metabolic rate. Applications of the homomorphism principle to assess variations in mass coefficient and exponent for intraspecific analysis of metabolism in reptiles are discussed. B. moojeni had an oxygen consumption in the range reported for viperids, but lower than that for colubrid snakes of similar size. Possible causative reasons for this pattern is discussed.

Oxygen consumption of the amphibious snail Pomacea lineata; Influence of weight, sex and environments

1. 1. Under normoxic conditions at 25°C Pomacea lineata, free to move into or out of water, showed an increase in O2 consumption with increase in body size (dry wt), the slope of the log-log plot of these two parameters being b = 0.76. 2. 2. The metabolic rate decreased with weight. 3. 3. Males and females in a sexually receptive state did not exhibit significantly different QO2 values. 4. 4. The metabolic rates of animals when under water using ctenidium did not differ significantly from when out of water using the lung. © 1981.

Cardiac cachexia

Patients with chronic heart failure (CHF) may develop a wasting syndrome, termed cardiac cachexia. This condition should be diagnosed when weight loss of more than 7.5% of the premorbid normal weight occurs over a time period of more than 6 months. Although the pathophysiologic causes of body wasting in patients with CHF remain unclear, studies have suggested that reduction of the dietary ingestion, intestinal malabsorption of nutrients, increased resting metabolic rates, and humoral neuroendocrine and immunologic abnormalities may play a role. The development of cachexia in the patients with CHF results in clinical symptoms, adverse consequences on the heart, and impaired survival.

Nucleolar changes in malpighian tubules cells of Rhodnius prolixus during starvation

This study focused on nuclear and nucleolar area changes in Malpighian tubule cells of Rhodnius prolixus, an hematophagous insect, vector of Chagas' disease. Male and female adult insects were dissected after a 28-day starvation period, as well as insects which had been fed again after a 30-day starvation period. Malpighian tubules were fixed and silver stained. In both, males and females, nucleolar fusions and regions of nucleolar corpuscles were observed to be differentially impregnated by silver during feeding stress. In the males and females that were fed again, nucleolar corpuscles were partially fusioned, indicating a slight recovery upon the 30-day starvation period. The changes observed in the nucleolar phenotype and in both nuclear and nucleolar areas indicated that, as a result of stress, a more intense, compensatory activity occurred to supply the metabolic rate. The mechanism of this phenomenon may be associated to the decondensation and activation of chromatin that carries rDNA in order to increase rRNA transcription, and,consequently, protein synthesis.

Efeitos da prática da natação adaptada sobre o perfil bioquímico e o estado de condicionamento físico de indivíduos com lesão medular

Introduction: The lack of physical exercises generated by immobilization of the lower limbs leads to changes in body composition that are generally associated with the imbalance of metabolic rate coupled with a sedentary status, which can result in obesity, diabetes mellitus and cardiovascular disease. Therefore, the improvement of physical fitness can contribute to promoting health and quality of life for these patients. As there is a very small number of research in this direction, our purpose was to investigate the effects of an adapted swimming program in protocol interval, for people with spinal cord injury, aiming to verify the improvement of your fitness and, consequently, some biochemical variables important for health. Methodology: The study included 17 subjects with spinal cord injury, sedentary, divided into two groups: 11 participants in the training group (TG) and 6 in control group (CG). TG was applied by a protocol of interval training in swimming for eight consecutive weeks, three times a week. The protocol employed a stroke of breaststroke in work periods of moderate to severe, and stroke in the backstroke, in periods of active recovery. The CG has not participated in any physical activity. Both groups were collecting blood for biochemical analysis, before (evaluation) and after (revaluation) the swimming program. Results and Discussion: The concentrations of triglycerides, total cholesterol and LDL-cholesterol showed no significant changes in assessment for reassessment in both groups. However the TG, the level of HDL-cholesterol were significant differences (p=0,0110), showing an improvement in posttraining, which did not occur in the CG. With respect to the state of fitness, the results revealed a significant difference in relation to time and distance covered in water when compared with the pre-training (p<0,001), showing a great improvement in the ability to shift with the stroke of breaststroke and a significant improvement in cardiorespiratory function. Conclusion: The swimming program interval used, with moderate to severe intensity, can even in a short period of time, promote positive changes in HDLcholesterol in individuals with spinal cord injury studied, and substantially improve your fitness.

Balance of pH of chicks from eggs injected with ascorbic acid and subjected to thermal stress

This study aimed to verify that chicks from eggs injected with ascorbic acid and subjected to heat stress would have changes in acid-base balance, compared to chicks incubated at thermoneutral without injection of ascorbic acid. The parameters evaluated were blood pressure of carbon dioxide and oxygen, base excess, total carbon dioxide, concentration of sodium, potassium, ionized calcium, bicarbonate and pH of newly hatched male chicks, hatched from eggs injected with acid ascorbic acid (AA) and subjected to heat stress during incubation. The experimental design was completely randomized in factorial scheme 5 (application levels of ascorbic acid) x 2 (incubation temperatures). The data were subjected to analysis of variance using the General Linear Model procedure (GLM) of SAS ®. For the blood pH was observed significant interaction (p <0.05) between treatments with application in eggs and incubation temperatures. For the other parameters were not significant effects (p< 0.05) of AA level and neither temperature of incubation. Analyzing the unfolding of the interaction to pH was observed that chicks from eggs injected with 6% ascorbic acid and subjected to heat stress during incubation had a higher pH value compared with the thermoneutral temperature incubated (p <0.05). Therefore, it is suggested that the incubation of eggs in high temperature (39°C) can alter the metabolic rate of these embryos.

Waist circumference, but not body mass index, is a predictor of ventricular remodeling after anterior myocardial infarction

Objective: The impact of obesity on ventricular remodeling after myocardial infarction (MI) is still poorly understood. Therefore, the aim of this study was to evaluate the role of waist circumference (WC) and body mass index as predictors of cardiac remodeling in patients after an anterior MI. Methods: Eighty-three consecutive patients with anterior MI were prospectively evaluated. Clinical characteristics and echocardiographic data were analyzed at admission and at a 6-mo follow-up. Ventricular remodeling was defined as a 10% increase in left ventricular end-systolic or end-diastolic diameter at the 6-mo follow-up. Results: In our study, 83 consecutive patients were evaluated (72% men). Ventricular remodeling was present in 31% of the patients (77% men). Patients with remodeling had higher creatine phosphokinase and creatine phosphokinase-MB peak values, a higher resting heart rate, a larger left atrial diameter, and a larger interventricular septum diastolic thickness. In addition, patients with remodeling had lower peak velocity of early ventricular filling deceleration time and ejection fraction. Patients with remodeling presented higher WC values (with remodeling, 99.2 ± 10.4 cm; without remodeling, 93.9 ± 10.8 cm, P = 0.04), but there were no differences in the body mass index values. In the logistic regression analysis, WC, adjusted by age, gender, ejection fraction, and creatine phosphokinase levels, was an independent predictor of left ventricular remodeling (odds ratio 1.067, 95% confidence interval 1.001-1.129, P = 0.02). Conclusion: Waist circumference, but not body mass index, is a predictor of ventricular remodeling after an anterior MI. Therefore, the WC of these patients should be measured in clinical practice. © 2013 Elsevier Inc.

Biostimulatory effect of low-level laser therapy on keratinocytes in vitro

Epithelial cells play an important role in reparative events. Therefore, therapies that can stimulate the proliferation and metabolism of these cells could accelerate the healing process. To evaluate the effects of low-level laser therapy (LLLT), human keratinocytes were irradiated with an InGaAsP diode laser prototype (LASERTable; 780 ± 3 nm; 40 mW) using 0.5, 1.5, 3, 5, and 7 J/cm2 energy doses. Irradiations were done every 24 h totaling three applications. Evaluation of cell metabolism (MTT assay) showed that LLLT with all energy doses promoted an increase of cell metabolism, being more effective for 0.5, 1.5, and 3 J/cm2. The highest cell counts (Trypan blue assay) were observed with 0.5, 3, and 5 J/cm2. No statistically significant difference for total protein (TP) production was observed and cell morphology analysis by scanning electron microscopy revealed that LLLT did not promote morphological alterations on the keratinocytes. Real-time polymerase chain reaction (qPCR) revealed that LLLT also promoted an increase of type I collagen (Col-I) and vascular endothelial growth factor (VEGF) gene expression, especially for 1.5 J/cm2, but no change on fibroblast growth factor-2 (FGF-2) expression was observed. LLLT at energy doses ranging from 0.5 to 3 J/cm2 promoted the most significant biostimulatory effects on cultured keratinocytes. © 2012 Springer-Verlag London Ltd.

Ablation of the ability to control the right-to-left cardiac shunt does not affect oxygen uptake, specific dynamic action or growth in the rattlesnake Crotalus durissus

The morphologically undivided ventricle of the heart in non-crocodilian reptiles permits the mixing of oxygen-rich blood returning from the lungs and oxygen-poor blood from the systemic circulation. A possible functional significance for this intra-cardiac shunt has been debated for almost a century. Unilateral left vagotomy rendered the single effective pulmonary artery of the South American rattlesnake, Crotalus durissus, unable to adjust the magnitude of blood flow to the lung. The higher constant perfusion of the lung circulation and the incapability of adjusting the right-left shunt in left-denervated snakes persisted over time, providing a unique model for investigation of the long-term consequences of cardiac shunting in a squamate. Oxygen uptake recorded at rest and during spontaneous and forced activity was not affected by removing control of the cardiac shunt. Furthermore, metabolic rate and energetic balance during the post-prandial metabolic increment, plus the food conversion efficiency and growth rate, were all similarly unaffected. These results show that control of cardiac shunting is not associated with a clear functional advantage in adjusting metabolic rate, effectiveness of digestion or growth rates. © 2013. Published by The Company of Biologists Ltd.