The purpose of this work was to discriminate between two models for glucose-6-phosphatase: one in which the enzyme has its catalytic site oriented toward the lumen of the endoplasmic reticulum, requiring transporters for glucose-6-phosphate, inorganic phosphate (Pi), and glucose (substrate-transport model), and a second one in which the hydrolysis of glucose-6-phosphate occurs inside the membra...

Rat epididymal fat pad segments were incubated with glucose labeled uniformly with W, and with tritium in position 2, and in positions 1,3, and 6. Under conditions of high lipogenesis, 70 to 80% of tritium (T) from position 2 was recovered in water, with the remainder in lipid glycerol, fatty acids, and lactate. The highest tritium retention, relative to carbon, was in glycerol, with T:W ratios...

Rat epididymal fat pad segments were incubated with glucose labeled uniformly with W, and with tritium in position 2, and in positions 1,3, and 6. Under conditions of high lipogenesis, 70 to 80% of tritium (T) from position 2 was recovered in water, with the remainder in lipid glycerol, fatty acids, and lactate. The highest tritium retention, relative to carbon, was in glycerol, with T:W ratios...