“…It has been shown that presence of DEX in islet or -cell culture medium induces reduction (Gremlich et al, 1997) or no change (Shao et al, 2004) in GLUT 2 protein content, decrease in -cell GK (Shao et al, 2004) and pyruvate dehydrogenase (PDH) (Arumugam et al, 2010) activities, and increased pyruvate dehydrogenase kinase (PDK)-2 mRNA content (Arumugam et al, 2010). Despite alterations of these proximal metabolic components, the failure of -cells' response to glucose does not appear to involve a defect in the recognition of glucose, because no changes in the rate of glucose oxidation (Lambillotte et al, 1997;Zawalich et al, 2006), oxygen consumption (Ortsäter et al, 2005), NAD(P)H production (Lambillotte et al, 1997), or [Ca 2+ ]i (Lambillotte et al, 1997) have been observed. There are controversies related to Ca 2+ influx in response to glucose or non-glucidic stimuli (Myrsén-Axcrona et al, 1997;Koizumi & Yada, 2008), but in spite of elevation or reduction in Ca 2+ influx, there is consensus that Ca 2+ oscillations are impaired, which may harm the distal events of secretion dependent of finely tuned Ca 2+ handling.…”