Matched pairs of malignant and non-malignant hybrid cells were compared in their response to glucose deprivation and to tunicamycin. Glucose deprivation induced an increase in the maximum velocity in the malignant cells, but not in the non-malignant cells. The Michaelis constant of hexose uptake was largely unchanged by glucose deprivation except in the case of one melanoma derivative, PG19 G-,...

Glia perform several energy-dependent functions that may aid neuronal survival under pathological conditions. Glycogen is the major energy reserve in brain, and it is localized almost exclusively to astrocytes. Using murine cortical cell cultures containing both glia and neurons, we examined the effect of altered glial glycogen stores on neuronal survival following glucose deprivation. As previ...

Cancer cells in poorly vascularized solid tumors are constantly or intermittently exposed to stressful microenvironments, including glucose deprivation, hypoxia, and other forms of nutrient starvation. These tumor-specific conditions, especially glucose deprivation, activate a signaling pathway called the unfolded protein response (UPR), which enhances cell survival by induction of the stress p...

Whether or not deprivation of glucose and oxygen can induce cardiomyocyte apoptosis was examined. Four groups of Langendorff preparations of guinea-pig hearts were perfused for 6 h with Krebs-Henseleit (K-H) solution deprived of glucose (group A), deprived of oxygen (group B), and deprived of both glucose and oxygen (group C), then examined for the mode of myocardial cell death. The control was...

Glucose depletion results in cellular stress and reactive oxygen species (ROS) production, which evokes adaptive and protective responses. One such protective response is the induction of haem oxygenase 1 (HO-1), which catalyses the rate-limiting step in haem degradation, liberating iron, CO and biliverdin. The present study evaluated the role of ROS and the mitochondrial electron-transport cha...

Surplus energy is principally stored in white adipose tissue (WAT) as triacylglycerol and mobilized via lipolysis through norepinephrine (NE) released from sympathetic nervous system terminals innervating WAT. We demonstrated that central melanocortin receptor agonism provokes differential sympathetic drives across WAT pads and interscapular brown adipose tissue (IBAT). Here we tested for diffe...

Cancer cells, relative to normal cells, demonstrate increased sensitivity to glucose-deprivation-induced cytotoxicity. To determine whether oxidative stress mediated by O(2)(*-) and hydroperoxides contributed to the differential susceptibility of human epithelial cancer cells to glucose deprivation, the oxidation of DHE (dihydroethidine; for O(2)(*-)) and CDCFH(2) [5- (and 6-)carboxy-2',7'-dich...

This report provides in vitro evidence that synaptic activity becomes resistant to repeated hypoglycemia, i.e., hypoglycemic synaptic adaptation occurs. Synaptic function was estimated by the amplitude of the postsynaptic population spike (PS) recorded in the granule cell layer of guinea pig hippocampal slices. ATP, phosphocreatine (PCr), glycogen, and glucose concentrations were measured to in...

The induction of proangiogenic cytokines such as vascular endothelial growth factor (VEGF) is a critical feature of tumor angiogenesis. In the present study, we examined the mechanisms of VEGF gene expression induced by glucose deprivation in cancer cells, a role of AMP-activated protein kinase (AMPK) in the process, and the signal transduction pathway. AMPK functions as an energy sensor to pro...