Metabolism via the pentose phosphate pathway in rat pheochromocytoma PC12 cells: effects of nerve growth factor and 6-aminonicotinamide.
Exposure of rat pheochromocytoma PC12 cells to 0.1 mM 6-aminonicotinamide (6AN) for 24 hours resulted in a 500-fold increase in 6-phosphogluconate indicating active metabolism of glucose via the oxidative enzymes of the pentose phosphate pathway. Amounts of 6-phosphogluconate that accumulated in 6AN-treated cells at 24 hours were significantly increased by treatment of the cells with nerve growth factor (NGF) (100 ng 7S/ml) suggesting that metabolism of glucose via the pentose pathway at this time was enhanced by NGF. This stimulation of metabolism via the pentose pathway is probably a late response to NGF because initial rates of 6-phosphogluconate accumulation in 6AN-treated cells were the same in the presence and absence of NGF. Moreover, amounts of 14CO2 generated from 1-[14CO2]glucose during the initial six hour incubation period were the same in control and NGF-treated cells. Specific activities of hexose phosphates labeled from 1-[14CO2]glucose were also the same in control and NGF-treated cells. The observation that 6AN inhibited metabolism via the pentose phosphate pathway but failed to inhibit NGF-stimulated neurite outgrowth suggests that NADPH required for lipid biosynthesis accompanying NGF-stimulated neurite outgrowth from PC12 cells can be derived from sources other than, or in addition to, the oxidative enzymes of the pentose phosphate pathway.
D015120:6-Aminonicotinamide / Q000494:pharmacology*; D000310:Adrenal Gland Neoplasms / Q000378:metabolism*; D000818:Animals; D002245:Carbon Dioxide / Q000378:metabolism; D002460:Cell Line; D005942:Gluconates / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D007700:Kinetics; D007773:Lactates / Q000378:metabolism; D019344:Lactic Acid; D009414:Nerve Growth Factors / Q000494:pharmacology*; D009536:Niacinamide / Q000031:analogs & derivatives*; D010427:Pentose Phosphate Pathway; D010673:Pheochromocytoma / Q000378:metabolism*; D051381:Rats
D005942:Gluconates; D007773:Lactates; D009414:Nerve Growth Factors; D002245:Carbon Dioxide; D009536:Niacinamide; D015120:6-Aminonicotinamide; D019344:Lactic Acid; D005947:Glucose; C008884:6-phosphogluconic acid