Biomaterial Database

Mechanism of delayed hepatic glycogen synthesis after an oral galactose load vs. an oral glucose load in adult rats. 1992

C B Niewoehner, and B Neil

Endocrine Metabolic Section, Veterans Affairs Medical Center, Minneapolis 55417.

We have compared the effects of administration of oral galactose or glucose (1 g/kg) to 24-h fasted rats to examine the mechanism by which galactose regulates its own incorporation into liver glycogen in vivo. Liver glycogen increased to a maximum more slowly after galactose than after glucose administration (0.14 vs. 0.29 mumol.g liver-1.min-1). Glycogen accumulation after the galactose load was 70% of that after the glucose load (149 vs. 214 mumol), and the net increase in liver glycogen represented the same proportion (24 vs. 22%) of added carbohydrate after urinary loss of galactose was accounted for. Slower glycogen accumulation after galactose vs. glucose loading could not be explained by galactosuria, by differences in the active forms of synthase or phosphorylase, by end product (glycogen) inhibition of synthase phosphatase, or by different concentrations of the known allosteric effectors of synthase R plus I and phosphorylase a. Similar increases in glucose 6-phosphate were observed after both hexoses. AMP and ADP increased only transiently after galactose administration, and ATP, UTP, and Pi concentrations were unchanged. The UDP-glucose concentration decreased, whereas the UDP-galactose concentration increased two- to threefold after galactose but not glucose administration. The UDP-glucose pyrophosphorylase reaction is inhibited competitively by UDP-galactose. This could explain the decreased UDP-glucose concentration and the reduced rate of glycogen synthesis after galactose was given.

UI	MeSH Term	Description	Entries
D008099	Liver	A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.	Livers
D008297	Male		Males
D009994	Osmolar Concentration	The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent.	Ionic Strength,Osmolality,Osmolarity,Concentration, Osmolar,Concentrations, Osmolar,Ionic Strengths,Osmolalities,Osmolar Concentrations,Osmolarities,Strength, Ionic,Strengths, Ionic
D011919	Rats, Inbred Strains	Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.	August Rats,Inbred Rat Strains,Inbred Strain of Rat,Inbred Strain of Rats,Inbred Strains of Rats,Rat, Inbred Strain,August Rat,Inbred Rat Strain,Inbred Strain Rat,Inbred Strain Rats,Inbred Strains Rat,Inbred Strains Rats,Rat Inbred Strain,Rat Inbred Strains,Rat Strain, Inbred,Rat Strains, Inbred,Rat, August,Rat, Inbred Strains,Rats Inbred Strain,Rats Inbred Strains,Rats, August,Rats, Inbred Strain,Strain Rat, Inbred,Strain Rats, Inbred,Strain, Inbred Rat,Strains, Inbred Rat
D001786	Blood Glucose	Glucose in blood.	Blood Sugar,Glucose, Blood,Sugar, Blood
D005690	Galactose	An aldohexose that occurs naturally in the D-form in lactose, cerebrosides, gangliosides, and mucoproteins. Deficiency of galactosyl-1-phosphate uridyltransferase (GALACTOSE-1-PHOSPHATE URIDYL-TRANSFERASE DEFICIENCY DISEASE) causes an error in galactose metabolism called GALACTOSEMIA, resulting in elevations of galactose in the blood.	D-Galactose,Galactopyranose,Galactopyranoside,D Galactose
D005693	Galactosemias	A group of inherited enzyme deficiencies which feature elevations of GALACTOSE in the blood. This condition may be associated with deficiencies of GALACTOKINASE; UDPGLUCOSE-HEXOSE-1-PHOSPHATE URIDYLYLTRANSFERASE; or UDPGLUCOSE 4-EPIMERASE. The classic form is caused by UDPglucose-Hexose-1-Phosphate Uridylyltransferase deficiency, and presents in infancy with FAILURE TO THRIVE; VOMITING; and INTRACRANIAL HYPERTENSION. Affected individuals also may develop MENTAL RETARDATION; JAUNDICE; hepatosplenomegaly; ovarian failure (PRIMARY OVARIAN INSUFFICIENCY); and cataracts. (From Menkes, Textbook of Child Neurology, 5th ed, pp61-3)	Galactokinase Deficiency Disease,Galactose-1-Phosphate Uridyl-Transferase Deficiency Disease,UDPglucose 4-Epimerase Deficiency Disease,Classic Galactosemia,Deficiency Disease, Galactokinase,Deficiency Disease, Galactose-1-Phosphate Uridyl-Transferase,Deficiency Disease, UDP-Galactose-4-Epimerase,Deficiency Disease, UDPglucose 4-Epimerase,Epimerase Deficiency Galactosemia,GALE Deficiency,GALK Deficiency,GALT Deficiency,Galactokinase Deficiency,Galactose Epimerase Deficiency,Galactose-1-Phosphate Uridyltransferase Deficiency,Galactose-1-Phosphate Uridylyltransferase Deficiency,Galactosemia,Galactosemia 2,Galactosemia 3,Galactosemia III,Galactosemia, Classic,Hereditary Galactokinase Deficiency,UDP-Galactose-4-Epimerase Deficiency,UDP-Galactose-4-Epimerase Deficiency Disease,UDPGlucose Hexose-1-Phosphate Uridylyltransferase Deficiency,UTP Hexose-1-Phosphate Uridylyltransferase Deficiency,UTP-Hexose-1-Phosphate Uridylyltransferase Deficiency Disease,Classic Galactosemias,Deficiencies, GALE,Deficiencies, GALK,Deficiencies, GALT,Deficiencies, Galactokinase,Deficiencies, Galactose Epimerase,Deficiencies, Galactose-1-Phosphate Uridyltransferase,Deficiencies, Galactose-1-Phosphate Uridylyltransferase,Deficiencies, Hereditary Galactokinase,Deficiencies, UDP-Galactose-4-Epimerase,Deficiency Disease, Galactose 1 Phosphate Uridyl Transferase,Deficiency Disease, UDP Galactose 4 Epimerase,Deficiency Disease, UDPglucose 4 Epimerase,Deficiency Diseases, UDP-Galactose-4-Epimerase,Deficiency Galactosemia, Epimerase,Deficiency Galactosemias, Epimerase,Deficiency, GALE,Deficiency, GALK,Deficiency, GALT,Deficiency, Galactokinase,Deficiency, Galactose Epimerase,Deficiency, Galactose-1-Phosphate Uridyltransferase,Deficiency, Galactose-1-Phosphate Uridylyltransferase,Deficiency, Hereditary Galactokinase,Deficiency, UDP-Galactose-4-Epimerase,Epimerase Deficiency Galactosemias,GALE Deficiencies,GALK Deficiencies,GALT Deficiencies,Galactokinase Deficiencies,Galactokinase Deficiencies, Hereditary,Galactokinase Deficiency Diseases,Galactokinase Deficiency, Hereditary,Galactose 1 Phosphate Uridyl Transferase Deficiency Disease,Galactose 1 Phosphate Uridyltransferase Deficiency,Galactose 1 Phosphate Uridylyltransferase Deficiency,Galactose Epimerase Deficiencies,Galactose-1-Phosphate Uridyltransferase Deficiencies,Galactose-1-Phosphate Uridylyltransferase Deficiencies,Galactosemia 2s,Galactosemia 3s,Galactosemia IIIs,Galactosemia, Epimerase Deficiency,Galactosemias, Classic,Galactosemias, Epimerase Deficiency,Hereditary Galactokinase Deficiencies,UDP Galactose 4 Epimerase Deficiency,UDP Galactose 4 Epimerase Deficiency Disease,UDP-Galactose-4-Epimerase Deficiencies,UDP-Galactose-4-Epimerase Deficiency Diseases,UDPGlucose Hexose 1 Phosphate Uridylyltransferase Deficiency,UDPglucose 4 Epimerase Deficiency Disease,UTP Hexose 1 Phosphate Uridylyltransferase Deficiency,UTP Hexose 1 Phosphate Uridylyltransferase Deficiency Disease,Uridyltransferase Deficiencies, Galactose-1-Phosphate,Uridyltransferase Deficiency, Galactose-1-Phosphate,Uridylyltransferase Deficiencies, Galactose-1-Phosphate,Uridylyltransferase Deficiency, Galactose-1-Phosphate
D005947	Glucose	A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement.	Dextrose,Anhydrous Dextrose,D-Glucose,Glucose Monohydrate,Glucose, (DL)-Isomer,Glucose, (alpha-D)-Isomer,Glucose, (beta-D)-Isomer,D Glucose,Dextrose, Anhydrous,Monohydrate, Glucose
D006003	Glycogen
D006006	Glycogen Synthase	An enzyme that catalyzes the transfer of D-glucose from UDPglucose into 1,4-alpha-D-glucosyl chains. EC 2.4.1.11.	Glycogen (Starch) Synthase,Glycogen Synthetase,Glycogen Synthase I,Synthase D,Synthase I,UDP-Glucose Glycogen Glucosyl Transferase,Synthase, Glycogen,Synthetase, Glycogen,UDP Glucose Glycogen Glucosyl Transferase