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Substrate preferences and glucose uptake in glibenclamide-resistant Leishmania parasites [An article from: Comparative Biochemistry and Physiology, Part C]
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Substrate preferences and glucose uptake in glibenclamide-resistant Leishmania parasites [An article from: Comparative Biochemistry and Physiology, Part C] | Digital

by N.L. Uzcategui (Author), K. Figarella (Author), N. Camacho (Author), Ponte-Su (Author)

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Binding:  Digital
Publisher:  Elsevier


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This digital document is a journal article from Comparative Biochemistry and Physiology, Part C, published by Elsevier in 2005. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.Description: Several drug-resistant mammalian cell types exhibit increased glycolytic rates, preferential synthesis of ATP through oxidative phosphorylation, and altered glucose transport. Herein we analyzed the influence of parasite growth phase on energy substrate uptake and use in a Leishmania strain [NR(Gr)] selected for resistance against glibenclamide. Glibenclamide is an ABC-transporter blocker which modulates the function of glucose transporters in some mammalian cells. Our results demonstrate for the first time that compared to glibenclamide-sensitive Leishmania, exponential phase glibenclamide-resistant parasites exhibit decreased use of glucose as energy substrate, decreased glucose uptake and decreased glucose transporter expression. However, compared to glibenclamide-sensitive cells, stationary phase resistant parasites display an increased use of amino acids as energy substrate and an increased activity of the enzymes hexokinase, phosphoglucose isomerase, and especially NAD^+-linked glutamate dehydrogenase. These results suggest that drug resistance in Leishmania involves a metabolic adaptation that promotes a stage dependent modulation of energy substrate uptake and use as a physiological response to the challenge imposed by drug pressure.
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