RESUMEN
We examined the capacity of high-intensity intermittent training (HI-IT) to facilitate the delivery of lipids to enzymes responsible for oxidation, a task performed by the carnitine palmitoyl transferase (CPT) system in the rat gastrocnemius muscle. Male adult Wistar rats (160-250 g) were randomly distributed into 3 groups: sedentary (Sed, N = 5), HI-IT (N = 10), and moderate-intensity continuous training (MI-CT, N = 10). The trained groups were exercised for 8 weeks with a 10% (HI-IT) and a 5% (MI-CT) overload. The HI-IT group presented 11.8% decreased weight gain compared to the Sed group. The maximal activities of CPT-I, CPT-II, and citrate synthase were all increased in the HI-IT group compared to the Sed group (P < 0.01), as also was gene expression, measured by RT-PCR, of fatty acid binding protein (FABP; P < 0.01) and lipoprotein lipase (LPL; P < 0.05). Lactate dehydrogenase also presented a higher maximal activity (nmol·min-1·mg protein-1) in HI-IT (around 83%). We suggest that 8 weeks of HI-IT enhance mitochondrial lipid transport capacity thus facilitating the oxidation process in the gastrocnemius muscle. This adaptation may also be associated with the decrease in weight gain observed in the animals and was concomitant to a higher gene expression of both FABP and LPL in HI-IT, suggesting that intermittent exercise is a "time-efficient" strategy inducing metabolic adaptation.
Asunto(s)
Animales , Masculino , Ratas , Carnitina O-Palmitoiltransferasa/metabolismo , Músculo Esquelético/enzimología , Condicionamiento Físico Animal/fisiología , Adaptación Fisiológica/fisiología , Lipoproteína Lipasa/metabolismo , Músculo Esquelético/metabolismo , Músculo Esquelético/fisiología , Oxidación-Reducción , Distribución Aleatoria , Ratas Wistar , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
We examined the capacity of high-intensity intermittent training (HI-IT) to facilitate the delivery of lipids to enzymes responsible for oxidation, a task performed by the carnitine palmitoyl transferase (CPT) system in the rat gastrocnemius muscle. Male adult Wistar rats (160-250 g) were randomly distributed into 3 groups: sedentary (Sed, N = 5), HI-IT (N = 10), and moderate-intensity continuous training (MI-CT, N = 10). The trained groups were exercised for 8 weeks with a 10% (HI-IT) and a 5% (MI-CT) overload. The HI-IT group presented 11.8% decreased weight gain compared to the Sed group. The maximal activities of CPT-I, CPT-II, and citrate synthase were all increased in the HI-IT group compared to the Sed group (P < 0.01), as also was gene expression, measured by RT-PCR, of fatty acid binding protein (FABP; P < 0.01) and lipoprotein lipase (LPL; P < 0.05). Lactate dehydrogenase also presented a higher maximal activity (nmol·min(-1)·mg protein(-1)) in HI-IT (around 83%). We suggest that 8 weeks of HI-IT enhance mitochondrial lipid transport capacity thus facilitating the oxidation process in the gastrocnemius muscle. This adaptation may also be associated with the decrease in weight gain observed in the animals and was concomitant to a higher gene expression of both FABP and LPL in HI-IT, suggesting that intermittent exercise is a "time-efficient" strategy inducing metabolic adaptation.
Asunto(s)
Carnitina O-Palmitoiltransferasa/metabolismo , Músculo Esquelético/enzimología , Condicionamiento Físico Animal/fisiología , Adaptación Fisiológica/fisiología , Animales , Lipoproteína Lipasa/metabolismo , Masculino , Músculo Esquelético/metabolismo , Músculo Esquelético/fisiología , Oxidación-Reducción , Distribución Aleatoria , Ratas , Ratas Wistar , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
OBJECTIVES: To determine whether peroxide loads infused with total parenteral nutrition (TPN) are fully quenched by premature infants. STUDY DESIGN: After baseline urine peroxide levels were established, the effect of various parenteral regimens was correlated with urinary peroxide levels in 64 newborn infants
Asunto(s)
Recien Nacido Prematuro/orina , Nutrición Parenteral Total , Peróxidos/orina , Fototerapia , Aminoácidos/administración & dosificación , Estudios de Casos y Controles , Femenino , Alimentos Formulados , Glucosa/administración & dosificación , Humanos , Recién Nacido , Luz , Masculino , Proyectos Piloto , Vitaminas/administración & dosificaciónRESUMEN
The hypothesis that a high-fat parenteral regimen was beneficial for respiratory gas exchanges, in comparison with a high-glucose regimen, was tested in a paired crossover design. Ten parenterally fed newborn infants with no respiratory problems received two 5-day isoenergetic and isonitrogenous regimens that differed in their nonprotein source of energy; the level of fat intake (low fat (LF) 1 gm.kg-1.day-1; high fat (HF) 3 gm.kg-1.day-1) varied inversely with that of glucose. Continuous transcutaneous PO2 (tcPO2) and PCO2 (tcPCO2), respiratory gas exchange (indirect calorimetry), and plasma arachidonate metabolites were measured at the end of each regimen. Oxygen consumption and resting energy expenditure were not affected by modification of the source of energy. However, carbon dioxide production (VCO2) was higher during LF than during HF (6.9 +/- 0.2 vs 6.2 +/- 0.1 ml.kg-1.min-1; p less than 0.01), as was the respiratory quotient (1.08 +/- 0.02 vs 0.96 +/- 0.02; p less than 0.001). Despite the differences in VCO2, the tcPCO2 was not affected, suggesting adequate pulmonary compensation during LF, as documented by the higher minute ventilation (160 +/- 7 vs 142 +/- 5 ml.kg-1.min-1; p less than 0.01). The lower tcPO2 during the HF regimen (73.8 +/- 2.8 vs 68.8 +/- 2.6 mm Hg; p less than 0.015) indicated a disturbance at the alveolocapillary level induced by the lipid emulsion. No differences were found in circulating levels of prostaglandins and thromboxanes. The substitution of glucose for lipid did not modify fat storage (2.1 +/- 0.3 vs 2.1 +/- 0.3 gm.kg-1.day-1). We conclude that the supposed beneficial effect of a fat emulsion on respiratory gas exchange is questionable.
Asunto(s)
Calorimetría Indirecta , Grasas de la Dieta/metabolismo , Metabolismo Energético , Glucosa/metabolismo , Recién Nacido/metabolismo , Metabolismo de los Lípidos , Nutrición Parenteral Total/métodos , Monitoreo de Gas Sanguíneo Transcutáneo , Humanos , Alimentos Infantiles , Consumo de Oxígeno/fisiologíaRESUMEN
"The objective of the research program presented in this note is to analyse the interrelations between biological and social factors in the process of demographic renewal. Population registers of various communities, among them those of Saint-Barthelemy (French Antilles) and Ile-aux-Coudres (Quebec), are used. The genealogies which were obtained from these registers contribute to the study of genetical epidemiology. The research program also includes the identification of social factors which may have contributed to the biological structure of the communities under study." (SUMMARY IN ENG AND SPA)