AMP-Activated Protein Kinase Plays an Important Evolutionary Conserved Role in the Regulation of Glucose Metabolism in Fish Skeletal Muscle Cells

AMPK, a master metabolic switch, mediates the observed increase of glucose uptake in locomotory muscle of mammals during exercise. AMPK is activated by changes in the intracellular AMP∶ATP ratio when ATP consumption is stimulated by contractile activity but also by AICAR and metformin, compounds that increase glucose transport in mammalian muscle cells. However, the possible role of AMPK in the regulation of glucose metabolism in skeletal muscle has not been investigated in other vertebrates, including fish. In this study, we investigated the effects of AMPK activators on glucose uptake, AMPK activity, cell surface levels of trout GLUT4 and expression of GLUT1 and GLUT4 as well as the expression of enzymes regulating glucose disposal and PGC1α in trout myotubes derived from a primary muscle cell culture. We show that AICAR and metformin significantly stimulated glucose uptake (1.6 and 1.3 fold, respectively) and that Compound C completely abrogated the stimulatory effects of the AMPK activators on glucose uptake. The combination of insulin and AMPK activators did not result in additive nor synergistic effects on glucose uptake. Moreover, exposure of trout myotubes to AICAR and metformin resulted in an increase in AMPK activity (3.8 and 3 fold, respectively). We also provide evidence suggesting that stimulation of glucose uptake by AMPK activators in trout myotubes may take place, at least in part, by increasing the cell surface and mRNA levels of trout GLUT4. Finally, AICAR increased the mRNA levels of genes involved in glucose disposal (hexokinase, 6-phosphofructokinase, pyruvate kinase and citrate synthase) and mitochondrial biogenesis (PGC-1α) and did not affect glycogen content or glycogen synthase mRNA levels in trout myotubes. Therefore, we provide evidence, for the first time in non-mammalian vertebrates, suggesting a potentially important role of AMPK in stimulating glucose uptake and utilization in the skeletal muscle of fish

Structural diversity and photo-physical and magnetic properties of dimeric to 1D polymeric coordination polymers of lighter lanthanide(III) dinitrobenzoates

International audienc

Structural and magnetic investigations of a binuclear coordination compound of dysprosium(iii) dinitrobenzoate

International audienc

The impact of capital structure on firm performance and risk in Finland

The decision pertaining to the capital structure is one of the most strategic, perpetual, and at the same time challenging corporate decisions. Having an optimum capital structure is an important aspect of the financing of firms. Firms often struggle to create an optimum balance between their debt and equity. The current chapter aims to explore whether the capital structure impacts the performance (financial and nonfinancial) and the financial risks of the firms in Finland. In the current chapter, the secondary data of 50 large-cap Finnish public firms listed at the Helsinki stock exchange has been obtained for the period 2011–2017. The findings of the research disclose that leverage affects most of the accounting, market, and hybrid performance measures negatively. On the other hand, the effect of leverage on the nonfinancial measures has been found to be insignificant. Similarly, a high level of leverage leads to increase in the total risk; however, it does not affect the systematic risk. The current chapter is one of the fewest studies that employed comprehensive analysis through multiple measures of firm performance, risk, and capital structure in the context of the Finnish corporate sector