Channeling of alpha-D-glucose 6-phosphate in tumoral islet cells exposed to D-galactose.
In human erythrocytes, in which the fractional turnover rate of glucose 6-phosphate is rather low, menadione increases to almost the same relative extent the oxidation of D-[U-14C]glucose and D-[U-14C]galactose. However, in pancreatic tumoral islet cells (RINm5F line), in which the fractional turnover rate of glucose 6-phosphate is considerably higher, menadione increases the oxidation of D-[1-14C]glucose but not that of D-[1-14C]galactose. These results suggest that alpha-D-glucose 6-phosphate generated from exogenous D-galactose is channeled preferentially into the glycolytic rather than pentose phosphate pathway. Such was no more the case, however, when the RINm5F cells were exposed simultaneously to both D-glucose and D-galactose.
D007516:Adenoma, Islet Cell / Q000378:metabolism*; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism; D005690:Galactose / Q000378:metabolism / Q000494:pharmacology*; D019298:Glucose-6-Phosphate; D005958:Glucosephosphates / Q000378:metabolism*; D006019:Glycolysis; D006801:Humans; D010190:Pancreatic Neoplasms / Q000378:metabolism*; D014812:Vitamin K / Q000494:pharmacology
D005958:Glucosephosphates; D014812:Vitamin K; D019298:Glucose-6-Phosphate; C031590:glucose-1-phosphate; D005690:Galactose