Glucose metabolism is vital to most mammalian cells, and the passage of glucose across cell membranes is facilitated by a family of integral membrane transporter proteins, the GLUTs. There are currently 14 members of the SLC2 family of GLUTs, several of which have been the focus of this series of reviews. The subject of the present review is GLUT3, which, as implied by its name, was the third glucose transporter to be cloned (Kayano T, Fukumoto H, Eddy RL, Fan YS, Byers MG, Shows TB, Bell GI. J Biol Chem 263: [15245][15246][15247][15248] 1988) and was originally designated as the neuronal GLUT. The overriding question that drove the early work on GLUT3 was why would neurons need a separate glucose transporter isoform? What is it about GLUT3 that specifically suits the needs of the highly metabolic and oxidative neuron with its high glucose demand? More recently, GLUT3 has been studied in other cell types with quite specific requirements for glucose, including sperm, preimplantation embryos, circulating white blood cells, and an array of carcinoma cell lines. The last are sufficiently varied and numerous to warrant a review of their own and will not be discussed here. However, for each of these cases, the same questions apply. Thus, the objective of this review is to discuss the properties and tissue and cellular localization of GLUT3 as well as the features of expression, function, and regulation that distinguish it from the rest of its family and make it uniquely suited as the mediator of glucose delivery to these specific cells.neurons; sperm; preimplantation embryo; white blood cells GLUCOSE METABOLISM IS VITAL to most mammalian cells, and the passage of glucose across cell membranes is facilitated by a family of integral membrane transporter proteins, the GLUTs. There are currently 14 members of the SLC2 family of GLUTs, several of which have been the focus of this series of reviews. The subject of the present review is GLUT3 which, as implied by its name, was the third glucose transporter to be cloned (62) and was originally designated as the neuronal glucose transporter. Together with GLUT1, -2, and -4, it comprises the Class 1 group of transporters (For review see Refs. 15,81,121). With the cloning of GLUT3, it became apparent that the brain did not rely exclusively on GLUT1 and that GLUT3 was highly and specifically expressed by neurons. Thus, GLUT3 became the third facilitative glucose transporter isoform with unique characteristics suited for cell-specific expression and function. GLUT2 is ideally suited for expression in liver and pancreas due to its high K m for glucose; GLUT4 and its translocation from intracellular vesicles to the cell surface facilitates insulin-stimulated glucose uptake in insulin-sensitive cells: muscle and fat. The overriding question that drove the early work in GLUT3 in the brain was: why would neurons need a separate glucose transporter isoform; what is it about GLUT3 that specifically suits the needs of the highly metabolic and oxidative neuron with its high glucose demand?...

Various lines of evidence indicate the presence of progressive pathophysiological processes occurring within the brains of patients with schizophrenia. By modulating chemical neurotransmission, anti-psychotic drugs may influence a variety of functions regulating neuronal resilience and viability and have the potential for neuroprotection. This article reviews the current literature describing preclinical and clinical studies that evaluate the efficacy of antipsychotic drugs, their mechanism of action and the potential of first- and second-generation antipsychotic drugs to exert effects on cellular processes that may be neuroprotective in schizophrenia. The evidence to date suggests that although all antipsychotic drugs have the ability to reduce psychotic symptoms via D2 receptor antagonism, some antipsychotics may differ in other pharmacological properties and their capacities to mitigate and possibly reverse cellular processes that may underlie the pathophysiology of schizophrenia.