Does the pentose cycle play a major role for NADPH supply in the heart?
- PMID: 3790254
- DOI: 10.1515/bchm3.1986.367.2.1061
Does the pentose cycle play a major role for NADPH supply in the heart?
Abstract
It was attempted to determine the substrate flux through the pentose cycle in isolated rat hearts which performed pressure-volume work employing 14CO2 production from [1-14C]glucose (Kühn & Scholz (1982) Eur. J. Biochem. 124, 611-617). Even under conditions of increased NADPH requirements (infusion of tert-butylhydroperoxide) and a diminished 14CO2 production from glucose via the citrate cycle (in the presence of oleate as additional substrate) or enhanced activity of glucose-6-phosphate dehydrogenase (pretreatment with isoproterenol), a substrate flux through the pentose cycle was not detectable. The lower limit of detection is 0.01 mumol/(min X g). The increase in 14CO2 production from [1-14C]- and [6-14C]glucose and the acceleration in the washout when tert-butylhydroperoxide was present suggest an increase of substrate flux through the citrate cycle; therefore it is concluded that NADPH required for the removal of peroxides via the glutathione system is derived from the isocitrate dehydrogenase reaction.
Similar articles
-
Possible mechanisms for the anticonvulsant activity of fructose-1,6-diphosphate.Epilepsia. 2008 Nov;49 Suppl 8(Suppl 8):101-3. doi: 10.1111/j.1528-1167.2008.01849.x. Epilepsia. 2008. PMID: 19049602 Free PMC article. Review.
-
Regulation of and intervention into the oxidative pentose phosphate pathway and adenine nucleotide metabolism in the heart.Mol Cell Biochem. 1996 Jul-Aug;160-161:101-9. doi: 10.1007/BF00240038. Mol Cell Biochem. 1996. PMID: 8901462 Review.
-
Diminished pentose cycle flux in perfused livers of ethanol-fed rats.Mol Pharmacol. 1987 Jun;31(6):631-7. Mol Pharmacol. 1987. PMID: 3600608
-
tert.-Butyl hydroperoxide metabolism and stimulation of the pentose phosphate pathway in isolated rat hepatocytes.Toxicol Appl Pharmacol. 1986 Sep 30;85(3):324-31. doi: 10.1016/0041-008x(86)90339-x. Toxicol Appl Pharmacol. 1986. PMID: 2945286
-
Effect of anisotonic cell-volume modulation on glutathione-S-conjugate release, t-butylhydroperoxide metabolism and the pentose-phosphate shunt in perfused rat liver.Eur J Biochem. 1992 Oct 1;209(1):437-44. doi: 10.1111/j.1432-1033.1992.tb17307.x. Eur J Biochem. 1992. PMID: 1396717
Cited by
-
Considerations for using isolated cell systems to understand cardiac metabolism and biology.J Mol Cell Cardiol. 2021 Apr;153:26-41. doi: 10.1016/j.yjmcc.2020.12.007. Epub 2020 Dec 21. J Mol Cell Cardiol. 2021. PMID: 33359038 Free PMC article. Review.
-
Evidence for transaldolase activity in the isolated heart supplied with [U-13C3]glycerol.J Biol Chem. 2013 Feb 1;288(5):2914-22. doi: 10.1074/jbc.M112.409441. Epub 2012 Dec 12. J Biol Chem. 2013. PMID: 23235149 Free PMC article.
-
Regulation of mitochondrial NADP-isocitrate dehydrogenase in rat heart during ischemia.Mol Cell Biochem. 2007 Jan;294(1-2):97-105. doi: 10.1007/s11010-006-9249-9. Epub 2006 Jul 6. Mol Cell Biochem. 2007. PMID: 16823514