The effects of a series of medium-chain fatty acids (C6-C12) on glucose metabolism in isolated acini from lactating rat mammary glands have been studied. Hexanoate (C6) octanoate (C8) and decanoate (C10), but not laurate (C12), decreased [1-14C]glucose conversion into [14C]lipid and the production of 14CO2 (an index of the pentose phosphate pathway). With hexanoate and octanoate, glucose utilization was decreased, whereas decanoate had a slight stimulatory effect on glucose utilization, but there was a large accumulation of lactate. Addition of dichloroacetate (an inhibitor of pyruvate dehydrogenase kinase) decreased this accumulation of lactate and stimulated the conversion of [1-14C]glucose into [14C]lipid and 14CO2. Insulin had no effect on the rate of glucose utilization in the presence of hexanoate. It stimulated the rate in the presence of octanoate and laurate and increased the conversion of [1-14C]glucose into [14C]lipid in the presence of octanoate, decanoate or laurate. The major fate of 1-14C-labelled medium-chain fatty acids (C6, C8 and C12) was conversion into [14C]lipid. The proportion converted into 14CO2 decreased with increasing chain length, whereas the rate of [14C]lipid formation increased. It is concluded that the interactions between medium-chain fatty acids and glucose metabolism represent a feed-back mechanism to control milk lipid synthesis, and this may be important when milk accumulates in the gland.

To study the effects of medium-chain triacylglycerols (MCT) on maternal lipid metabolism and pup growth, MCT (200 g/kg) were incorporated into a commercial chow diet and fed to lactating rats for 8-10 d. The results were compared with similar diets containing sunflower oil (polyunsaturated fatty acids; PUFA), tristearin (saturated fatty acid) or triolein (monounsaturated fatty acid). There was decreased food and energy intake with the MCT diet and this was accompanied by decreased (35 %) pup growth. All the high-fat diets inhibited lipogenesis in vivo in the lactating mammary gland, the order of effectiveness being PUFA > triolein > tristearin > MCT. Only the MCT diet increased the rate of hepatic lipogenesis (180 %). Experiments feeding an MCT meal containing [ l-14C]octanoate indicated that very little ( 3 4 % ) of the C was present in mammary gland lipid, unlike the findings with [l-'4C]triolein meal (40 YO). The major portion (65 %) of the absorbed [l-'4C]octanoate was oxidized to I4CO,. There was no evidence for adaptation of the mammary gland to increased dietary lipid uptake on the triolein or M C T diets. It is concluded that the decreased pup growth on the M C T diet is due in part to the decreased energy intake and to the inability of dietary medium-chain fatty acids to provide substrates for milk lipid synthesis.

By daily vaginal smears, uremic rats showed significantly greater prevalence of irregular estrous cycles compared with sham-operated controls (p < 0.02). There seems to be a correlation between the degree of renal failure and estrous cycle abnormalities. The lack of LH surge on the afternoon of proestrus, found in uremic animals, suggests a defect in the positive hypothalamic steroid feedback.

Segundo a Secretaria de Vigilância Sanitária do Ministério da Saúde, bebidas energéticas são identificadas como compostos líquidos prontos para o consumo, sendo estas constituídas de carboidratos, taurina, cafeína, glucoronolactona, inositol e vitaminas do complexo B. Existem poucas pesquisas sobre o uso de taurina contida em bebidas energéticas relacionado com a melhora de desempenho. Este trabalho teve como objetivo analisar as respostas metabólicas e hemodinâmicas decorrentes da administração da associação de taurina e cafeína durante teste ergoespirométrico em indivíduos fisicamente ativos. Para esse fim, 20 indivíduos do sexo masculino, 26 ± 4,32 anos e índice de massa corporal 23,79 ± 2,95, praticantes de atividades aeróbicas, foram submetidos a duas sessões de testes em cicloergômetro ligado a analisador metabólico de gases. O esquema das sessões foi duplo-cego e 60 minutos antes do início dos testes foi oferecida bebida experimental ou bebida placebo. Durante os testes, foram mensuradas: frequência cardíaca (FC), pressão arterial sistólica (PAS) e diastólica (PAD), lactato sanguíneo (Lac), percepção subjetiva de esforço por escala de Borg (PSE), consumo máximo de oxigênio (VO 2máx ), consumo de oxigênio no ponto de compensação respiratório (RCP), tempo de exercício (TE) e carga de trabalho (CAR). Para a análise dos dados, foi realizado um teste t pareado (p ≤ 0,05). Na carga de trabalho, os resultados indicaram que houve aumento de 10 watts com a administração da bebida experimental, contudo, sem significância estatística (BE: 342 ± 40,60; P: 332,50 ± 56,83). Os principais resultados deste estudo indicam que a administração de taurina contida em bebida energética não influenciou os resultados das variáveis investigadas. Assim, podemos concluir que a dose de 2g utilizada não foi capaz de aumentar o desempenho.Palavras-chave: desempenho, suplementação, ergogênico. ABSTRACTAccording to the Sanitary Surveillance Agency of the Ministry of Health, energy drinks are identified as liquid compounds ready for consumption, being made of carbohydrates, taurine, caffeine, glucoronolactone, inositol, and B-complex vitamins. Given the small number of studies on the use of taurine in energy drinks related to improved performance, this paper aimed to analyze the metabolic and haemodynamic responses resulted from the administration of the association of taurine and caffeine during an ergospyrometric test in physically active subjects. Therefore, twenty male individuals, 26 ±4.32 years and body mass 23.79 ±2.95, frequent practitioners of aerobic activities, were submitted to two test sessions in cycle ergometer hooked to a gas metabolic analyzer. The sessions schedule was double-blind, and 60 minutes before them the individuals were offered experimental drinks or placebo drinks. During the tests, the subjects were evaluated on the following variables: heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), blood lactate (Lac), subjective perceived exertion by Borg scale (SPE), maximum oxygen uptake ...

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