Abstract
Gluconeogenesis is defined as the net formation of glucose from non-carbohydrate precursors such as pyruvate, lactate, glycerol, and certain amino acids. It is crucial for survival because glucose, the primary substrate for a number of tissues, most notably the brain, is only available during feeding, and liver glycogen stores can only provide glucose for a few hours. Gluconeogenesis and glycolysis have many enzymes in common (Fig. 1). Exceptions are the enzymes that catalyze the four irreversible steps which ensure a unidirectional flux from pyruvate to glucose:
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Pyruvate carboxylase (PC)
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Phosphoenolpyruvate carboxykinase (PEPCK)
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Fructose-1,6-bisphosphatase (FBPase)
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Glucose-6-phosphatase (G-6-Pase)
Defects of all four gluconeogenic enzymes are known Common to all are the tendency to facile hypoglycemia induced by fasting and lactic acidosis due to failure to recycle lactate to glucose. The deficiency of G-6Pase (Chap. 5) and FBPase usually spare the brain, unless it is damaged by recurrent hypoglycemia. The deficiencies of PEPCK and PC are associated with a progressive neurodegenerative disorder which is usually fatal.
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References
Taunton OD, Greene HL. Stifel FB, Hofeldt FC, Lufkin EG, Hagler L, Herman X. Herman RH (1978) Fructose 1,6-diphosphatase deficiency, hypoglycemia and response of folate therapy in a mother and her daughter. Biochem Med 19: 260
Elpeleg ON, Nurvitz H, Branski D, Barash V (1989) Fructose 1,6-diphosphatase deficiency; a 20-year follow up. Am J Dis Child 143: 140–141
Baker L, Winegrad AI (1970) Fasting hypoglycaemia and metabolic acidosis associated with deficiency of hepatic fructose-1,6-diphosphatase deficiency; a 20-year follow up. Am J Dis Child 143: 140–142
Moses SW, Bashan N, Flasterstein BF, Rachmel A, Gutman A (1991) Fructose-1,6-diphosphatase deficiency in Israel. Isr J Med Sci 27: 1–4
Buhrdel P, Bohme HJ, Didt L (1990) Biochemical and clinical observations in four patients with fructose-1,6-diphosphatase deficiency. Eur J Pediatr 149: 514–6
Kinugasa A, Kusunaki T. Iwashima A (1979) Deficiency of glucose-6-phosphate dehydrogenase found in a case of fructose-1,6-diphosphatase deficiency. Pediatr Res 13: 1361–1364
Service FJ, Veneziale CM, Nelson RA, Ellefson RD, Go VLW (1975) Combined deficiency of glucose-6-phosphatase and fructose-1,6-diphosphatase. Studies of glucagon secretion and fuel utilization. Am J Med 64: 696–706
Menahem S, Adams S (1989) Severe acidosis in a neonate with pulmonary valve stenosis; a possible stress inducer of a fetal syndrome of fructose-1,6diphosphatase and aldolase deficiency. Acta Paediatr Scand 78: 800–803
Leonard JV, Hyland K, Furukawa N, Clayton PT (1991) Mitochondrial phosphoenol pyruvate carboxykinase deficiency. Eur J Pediatr 150: 198199
Buist NRM (1980) Is pyruvate carboxylase involved in the renal tubular reabsorption of bicarbonate? J Inherited Metab Dis 3: 113–116
Van Costes RN, Fernhoff PM, DeVivo DC (1991) Pyruvate carboxylase deficiency: a benign variant with normal development. Pediatr Res 30: 1–4
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Buist, N.R.M. (1995). Disorders of Gluconeogenesis. In: Fernandes, J., Saudubray, JM., Van den Berghe, G., Tada, K., Buist, N.R.M. (eds) Inborn Metabolic Diseases. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-662-03147-6_8
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DOI: https://doi.org/10.1007/978-3-662-03147-6_8
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