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Query: UMLS:C0020505 (hyperphagia)
 6,116 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cold-exposed rats exhibit hypermetabolism, hyperphagia, and increased glucose oxidation. Their counterregulatory hormone secretion is markedly elevated, while insulin levels fall acutely, gradually returning to basal during acclimation. We assessed both hepatic and peripheral sensitivity to insulin in rats in the basal state and after 5 days of cold (5 C) exposure. The contribution of gluconeogenesis to total glucose turnover was measured and compared to daily urinary corticosterone excretion. Hepatic glucose production was equally suppressed by the infusion of insulin at 1.2 mU/kg X min in both control and cold-acclimated rats, but enhanced hepatic sensitivity to low dose (0.6 mU/kg X min) insulin infusion was only observed after cold exposure. The metabolic clearance of glucose was elevated with cold stress and was insensitive to the infusion of insulin at either level. Insulin resistance was not observed. Urinary excretion of corticosterone and urea nitrogen were markedly increased, but creatinine excretion was unchanged, suggesting that the concurrent increase in gluconeogenesis resulted from increased protein intake rather than increased catabolism of muscle protein.
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PMID:Enhanced hepatic insulin sensitivity and peripheral glucose uptake in cold acclimating rats. 389 63

Obese Zucker rats exhibit marked hyperphagia when compared to lean littermates but deposit a smaller percentage of total dietary energy as body protein. This study was designed to determine the roles of skeletal muscle protein synthesis, protein degradation, RNA, or DNA in producing the lower muscle mass of obese rats. At 44 days, 3 hindlimb muscles, the extensor digitorum longus (EDL), the gastrocnemius and the plantaris were significantly smaller in the obese animals. At 72 days, the differences in weights of these muscles were more pronounced. Protein synthesis and degradation were determined in the soleus at 44 days of age using an in vitro whole muscle incubation technique. Protein synthesis rate was significantly decreased in the obese animals. These changes were accompanied by reductions in both RNA and DNA levels. Significant changes in nucleic acid levels were observed in both the red and white portions of the gastrocnemius muscle. These changes in the anabolic process of protein accretion appear to be sufficient to account for the reduced muscle mass in the obese Zucker rat.
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PMID:Skeletal muscle growth in lean and obese Zucker rats. 619 56

One of the first steps in a clinical approach to any obese subject should be focused on the reduction and/or normalization of any potential or existing metabolic abnormality. Overeating and/or unbalanced food intake remains the major element in the origin and maintenance of obesity. The reduction of energy intake is the basis of successful weight loss. In obese subjects there are huge amounts of energy stored, mainly in the adipose tissue, which are mobilized according to the size and duration of an energy deficit. Considerable studies have been devoted to finding the optimal dietary approach that would promote rapid weight loss while maximizing the depletion of adipose tissue and conserving body protein. During fasting adipose tissue lipolysis rate increases and liberated unesterified fatty acids are oxidized in muscle and liver. The liver produces ketones which are oxidized in muscle and brain. The energy need of the brain is not sufficiently covered by ketone oxidation, therefore additional glucose must be provided. The liver produces glucose by gluconeogenesis using amino acids from muscle protein. Because of limited protein sources, protein must be given during energy restricted diet. Besides protein also vitamins, minerals, trace elements, fiber, and linoleic acid must be substituted during fasting and during treatment with very low calorie diets. Meal replacements are helpful to fulfil all the requirements. There is consensus that the first step in dietary treatment is an energy restricted diet with a calorie deficit of at least 600 Kcal/day, but more than 800 Kcal/day must be provided, with all essential nutrients. Observing the regulations, weight reduction with appropriate diet plans improves metabolic disturbances.
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PMID:[Principles of dietary treatment of obesity]. 1102 88

Bears undergo annual cycles in body mass: rapid fattening in autumn (i.e., hyperphagia), and mass loss in winter (i.e., hibernation). To investigate how Japanese black bears (Ursus thibetanus japonicus) adapt to such extreme physiological conditions, we analyzed changes in the mRNA expression of energy metabolism-related genes in white adipose tissues and skeletal muscle throughout three physiological stages: normal activity (June), hyperphagia (November), and hibernation (March). During hyperphagia, quantitative real-time polymerase chain reaction analysis revealed the upregulation of de novo lipogenesis-related genes (e.g., fatty acid synthase and diacylglycerol O-acyltransferase 2) in white adipose tissue, although the bears had been maintained with a constant amount of food. In contrast, during the hibernation period, we observed a downregulation of genes involved in glycolysis (e.g., glucose transporter 4) and lipogenesis (e.g., acetyl-CoA carboxylase 1) and an upregulation of genes in fatty acid catabolism (e.g., carnitine palmitoyltransferase 1A) in both tissue types. In white adipose tissues, we observed upregulation of genes involved in glyceroneogenesis, including pyruvate carboxylase and phosphoenolpyruvate carboxykinase 1, suggesting that white adipose tissue plays a role in the recycling of circulating free fatty acids via re-esterification. In addition, the downregulation of genes involved in amino acid catabolism (e.g., alanine aminotransferase) and the TCA cycle (e.g., pyruvate carboxylase) indicated a role of skeletal muscle in muscle protein sparing and pyruvate recycling via the Cori cycle. These examples of coordinated transcriptional regulation would contribute to rapid mass gain during the pre-hibernation period and to energy preservation and efficient energy production during the hibernation period.
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PMID:Seasonal changes in the expression of energy metabolism-related genes in white adipose tissue and skeletal muscle in female Japanese black bears. 2688 Mar 64

Revealing the mechanisms underlying the reversible physiology of hibernation could have applications to both human and animal health as hibernation is often associated with disease-like states. The present study uses RNA-sequencing to reveal the tissue and seasonal transcriptional changes occurring in grizzly bears (Ursus arctos horribilis). Comparing hibernation to other seasons, bear adipose has a greater number of differentially expressed genes than liver and skeletal muscle. During hyperphagia, adipose has more than 900 differentially expressed genes compared to active season. Hibernation is characterized by reduced expression of genes associated with insulin signaling, muscle protein degradation, and urea production, and increased expression within muscle protein anabolic pathways. Across all three tissues we find a subset of shared differentially expressed genes, some of which are uncharacterized, that together may reflect a common regulatory mechanism. The identified gene families could be useful for developing novel therapeutics to treat human and animal diseases.
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PMID:Hibernation induces widespread transcriptional remodeling in metabolic tissues of the grizzly bear. 3240 83