Glycogen hydrolysis

Quachi, T. T, Duchermin, A. M., Rose, C., and Schwartz, J. C., 1980, H-Glycogen hydrolysis elicited by histamine in mouse brain slices Selective involvement of H, receptors. Mol. Pharmacol. 17 301-308. 

D-glucose, dextrose, C Hi20 . The most common hexose sugar. It is present in many plants, and is the sugar of the blood. It is a constituent of starch, cellulose, glycogen, sucrose and many glycosides, from all of which it can be obtained by hydrolysis with acids or enzymes. 

Nucleophilic attack by water generally results in the cleavage of the amide, glycoside, or ester bonds that hold biopolymers together. This process is termed hydrolysis. Conversely, when monomer units are joined together to form biopolymers such as proteins or glycogen, water is a product, as shown below for the formation of a peptide bond between two amino acids. 

Carbohydrates are classified based upon the products formed when they are hydrolyzed. Monosaccharides are simple sugars that cannot be broken down into simpler sugars upon hydrolysis. Examples of monosaccharides are glucose, ribose, deoxyribose, and fructose. Disaccharides contain two monosaccharide units and yield two monosaccharides upon hydrolysis. Examples of disaccharides are lactose, maltose, and sucrose. Polysaccharides are polymers of monosaccharide units and yield many individual monosaccharides upon hydrolysis. Examples of polysaccharides are starch, glycogen, and cellulose. 

Linamurin is the principal cyanogenic glycoside in cassava its toxicity is due to hydrolysis by intestinal microflora releasing free cyanide (Padmaja and Panikkar 1989). Rabbits (Oryctolagus cuniculus) fed 1.43 mg linamurin/kg BW daily (10 mg/kg BW weekly) for 24 weeks showed effects similar to those of rabbits fed 0.3 mg KCN/kg BW weekly. Specihc effects produced by linamurin and KCN included elevated lactic acid in heart, brain, and liver reduced glycogen in liver and brain and marked depletion in brain phospholipids (Padmaja and Panikkar 1989). 

Amylases are hydrolytic enzymes which catalyze the hydrolysis of starches and glycogens. In addition to their intrinsic importance in Now with Bureau of Human Nutrition and Home Economics, U. S. Department of Agriculture, Beltsville, Maryland. 

The first step in glycolysis is the phosphorylation of glucose to give the ester glucose 6-phosphate. The glucose starting material may well have come from hydrolysis of starch obtained in the diet, or by utilization of glycogen reserves. 

Amylase, the most important endoglyco-sidase in the pancreas, catalyzes the hydrolysis of al 4 bonds in the polymeric carbohydrates starch and glycogen. This releases maltose, maltotriose, and a mixture of other oligosaccharides. 

This enzyme [EC 3.2.1.10] (also referred to as oUgo-1,6-glucosidase, sucrase-isomaltase, and limit dextrinase) catalyzes the hydrolysis of l,6-o -D-glucosidic linkages in isomaltose and dextrin products generated from starch and glycogen via a-amylase. See also Sucrase... 

Pyridoxine is present in food in the free form and as a glucoside, which may undergo partial hydrolysis in the gut lumen, or may be absorbed intact. Although pyridoxine is associated with the enzyme glycogen phosphorylase in muscles, it is not released in response to a dietary deficiency therefore it cannot be regarded as a storage form of the vitamin. 

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