Fabienne Rajas

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BACKGROUND & AIMS Glucose-6 phosphatase (Glc6Pase) is the last enzyme of gluconeogenesis and glycogenolysis, previously assumed to be expressed in the liver and kidney only, conferring on both tissues the capacity to produce endogenous glucose in blood. METHODS Using Northern blotting and reverse-transcription polymerase chain reaction and a highly(More)
At variance with the current view that only liver and kidney are gluconeogenic organs, because both are the only tissues to express glucose-6-phosphatase (Glc6Pase), we have recently demonstrated that the Glc6Pase gene is expressed in the small intestine in rats and humans and that it is induced in insulinopenic states such as fasting and diabetes. We used(More)
BACKGROUND AND AIMS Glycogen storage disease type 1a (GSD1a) is an inherited disease caused by a deficiency in the catalytic subunit of the glucose-6 phosphatase enzyme (G6Pase). GSD1a is characterized by hypoglycaemia, hyperlipidemia, and lactic acidosis with associated hepatic (including hepatocellular adenomas), renal, and intestinal disorders. A total(More)
PEPCK is a key enzyme of gluconeogenesis in liver and kidney. Recently, we have shown that small intestine also contributes to the endogenous glucose production in insulinopenia in rats and that glutamine is the main precursor of glucose synthesized in this tissue. The expression of the PEPCK gene in rat and human small intestine and the effect of(More)
The GK rat model of type 2 diabetes is especially convenient to dissect the pathogenic mechanism necessary for the emergence of overt diabetes because all adult rats obtained in our department (GK/Par colony) to date have stable basal mild hyperglycemia and because overt diabetes is preceded by a period of normoglycemia, ranging from birth to weaning. The(More)
Insulin initiates diverse hepatic metabolic responses, including gluconeogenic suppression and induction of glycogen synthesis and lipogenesis. The liver possesses a rich sinusoidal capillary network with a higher degree of hypoxia and lower gluconeogenesis in the perivenous zone as compared to the rest of the organ. Here, we show that diverse vascular(More)
Gluconeogenesis is induced in both the liver and intestine by increased cAMP levels. However, hepatic and intestinal glucose production can have opposite effects on glucose homeostasis. Glucose release into the portal vein by the intestine increases glucose uptake and reduces food intake. In contrast, glucose production by the liver contributes to(More)
The objectives of this study were to identify potential alterations in gene expression of melanocortin-4 receptor (MC4-R), proopiomelanocortin (POMC), and Agouti-related protein (AgRP) in mouse hypothalamus under a chronic peripheral infusion of leptin or at early (8 weeks) and advanced (16 weeks) phases of diet-induced obesity. Control or diet-induced(More)
OBJECTIVE Since the pioneering work of Claude Bernard, the scientific community has considered the liver to be the major source of endogenous glucose production in all postabsorptive situations. Nevertheless, the kidneys and intestine can also produce glucose in blood, particularly during fasting and under protein feeding. The aim of this study was to(More)
Glycogen storage disease type 1a (GSD1a) is caused by mutations in the gene of glucose-6 phosphatase (G6PC), encoding the last enzyme of gluconeogenesis and glycogenolysis. To study the effect of mutations previously identified, but not yet enzymatically characterized, in French GSD1a patients, we used an in vitro expression system of the human glucose-6(More)