Metabolic reprogramming involving glycolysis in the hibernating brown bear skeletal muscle

Background: In mammals, the hibernating state is characterized by biochemical adjustments, which include metabolic rate depression and a shift in the primary fuel oxidized from carbohydrates to lipids. A number of studies of hibernating species report an upregulation of the levels and/or activity of lipid oxidizing enzymes in muscles during torpor, with a concomitant downregulation for glycolytic enzymes. However, other studies provide contrasting data about the regulation of fuel utilization in skeletal muscles during hibernation. Bears hibernate with only moderate hypothermia but with a drop in metabolic rate down to ~ 25% of basal metabolism. To gain insights into how fuel metabolism is regulated in hibernating bear skeletal muscles, we examined the vastus lateralis proteome and other changes elicited in brown bears during hibernation. Results: We show that bear muscle metabolic reorganization is in line with a suppression of ATP turnover. Regulation of muscle enzyme expression and activity, as well as of circulating metabolite profiles, highlighted a preference for lipid substrates during hibernation, although the data suggested that muscular lipid oxidation levels decreased due to metabolic rate depression. Our data also supported maintenance of muscle glycolysis that could be fuelled from liver gluconeogenesis and mobilization of muscle glycogen stores. During hibernation, our data also suggest that carbohydrate metabolism in bear muscle, as well as protein sparing, could be controlled, in part, by actions of n-3 polyunsaturated fatty acids like docosahexaenoic acid. Conclusions: Our work shows that molecular mechanisms in hibernating bear skeletal muscle, which appear consistent with a hypometabolic state, likely contribute to energy and protein savings. Maintenance of glycolysis could help to sustain muscle functionality for situations such as an unexpected exit from hibernation that would require a rapid increase in ATP production for muscle contraction. The molecular data we report here for skeletal muscles of bears hibernating at near normal body temperature represent a signature of muscle preservation despite atrophying conditions

As Apocynaceae s. str. da região de Bauru, São Paulo, Brasil The Apocynaceae s. str. of the Bauru region, São Paulo State, Brazil

Este trabalho consistiu no levantamento das Apocynaceae na Região de Bauru, centro-oeste do estado de São Paulo, em diferentes tipos de vegetação. Foram encontradas 25 espécies, distribuídas em 15 gêneros, representadas nesta ordem: Forsteronia G. Mey., cinco espécies; Aspidosperma Mart., quatro espécies; Mandevilla Lindl., três espécies; Prestonia R. Br., duas espécies, e Condylocarpon Desf., Hancornia Gomez, Himatanthus Willd. ex Roem. et Schult., Macrosiphonia Müll.Arg., Mesechites Müll.Arg., Odontadenia Benth., Peltastes Woodson, Rhodocalyx Müll.Arg., Secondatia A. DC., Tabernaemontana L. e Temnadenia Miers, uma espécie cada. São apresentadas chaves de identificação, descrições e ilustrações das espécies, além de dados de distribuição geográfica, floração e frutificação.<br>The present study describes a survey of the Apocynaceae in different types of vegetation, in the region of Bauru, in the Center-West of São Paulo State. Of the 25 species encountered, distributed into 15 genera, representation ranges as follows: Forsteronia G. Mey, five species; Aspidosperma Mart., four species; Mandevilla Lindl., three species; Prestonia R. Br., two species; and Condylocarpon Desf., Hancornia Gomez, Himatanthus Willd. ex Roem. et Schult., Macrosiphonia Müll. Arg., Mesechites Müll. Arg., Odontadenia Benth, Peltastes Woodson, Rhodocalyx Müll Arg., Secondatia A. DC., Tabernaemontana L. and Temnadenia Miers, one species each. In addition to both distribution data, and flowering and fruiting times, identifications keys, descriptions and illustrations of the species are presented