Elimination of glucose contamination from adipocyte glycogen extracts.
Glycogen was quantified in rat adipocytes by isolation using conventional KOH digestion and ethanol precipitation, followed by hydrolysis and spectrophotometric assay of the glucose product. A concentration of 0.193+/-0.020 micromol glucosyl units/10(6)cells was recorded. When this procedure was modified by including a 4h incubation with glucose oxidase prior to glycogen hydrolysis, the glycogen concentration was found to be 0.055+/-0.008 micromol glucosyl units/10(6) cells. Therefore in adipocytes, conventional glycogen assays give substantial overestimates due to incomplete removal of glucose during glycogen isolation. Contaminant glucose can be scavenged in a simple manner by incubation with glucose oxidase prior to glycogen hydrolysis.
Nunes
Patricia M
PM
Center for Neurosciences and Cell Biology, Department of Zoology, University of Coimbra, 3004-517 Coimbra, Portugal.
Carvalho
Eugénia
E
Jones
John G
JG
D017667:Adipocytes / Q000166:cytology / Q000378:metabolism*; D000818:Animals; D005087:Glucan 1,4-alpha-Glucosidase / Q000378:metabolism; D005947:Glucose / Q000737:chemistry / Q000302:isolation & purification*; D005949:Glucose Oxidase / Q000378:metabolism; D006003:Glycogen / Q000737:chemistry* / Q000378:metabolism; D006868:Hydrolysis; D008297:Male; D051381:Rats; D017208:Rats, Wistar
D006003:Glycogen; D005949:Glucose Oxidase; D005087:Glucan 1,4-alpha-Glucosidase; D005947:Glucose