Journal article
Reversal of hyperglycemic-induced defects in myo-inositol metabolism and Na+/K+ pump activity in cultured neuroblastoma cells by normalizing glucose levels
Metabolism, clinical and experimental, Vol.42(9), pp.1180-1189
1993
DOI: 10.1016/0026-0495(93)90278-V
PMID: 8412773
Abstract
myo-Inositol accumulation and incorporation into phosphoinositides was decreased in neuroblastoma cells chronically exposed to medium containing 30 mmol/L glucose or 30 mmol/L galactose. In addition, the intracellular content of myo-inositol and phosphatidylinositol was decreased and the sorbitol or galactitol content increased in cells cultured for 2 weeks in medium containing 30 mmol/L glucose or 30 mmol/L galactose, respectively. Math Eq adenosine triphosphatase (ATPase) transport activity was also significantly decreased by long-term exposure of neuroblastoma cells to medium containing 30 mmol/L glucose or 30 mmol/L galactose. When glucose-conditioned cells were placed in medium containing a normal glucose concentration for 24 hours, myo-inositol metabolism and content, phosphatidylinositol levels, and Math Eq pump activity were restored or completely returned to normal values. These functions were also significantly improved, except for the phosphatidylinositol content, which was increased by 55%, when galactose-conditioned cells were incubated for 24 hours in unsupplemented medium. The polyol content of the glucose- or galactose-conditioned cells was also significantly reduced. Returning the cells to normal glucose levels for 1 to 3 hours did not completely restore myo-inositol metabolism. Improved myo-inositol metabolism and content, sorbitol levels, and Math Eq ATPase transport activity were also obtained within 24 hours when cells chronically exposed to medium supplemented with 30 mmol/L glucose were placed in medium containing 30 mmol/L glucose and 0.4 mmol/L sorbinil. The phosphatidylinositol content of these cells was improved by approximately 30%. Cells prelabeled for 24 hours with [U-14C]sorbitol metabolize more than 50% of the [U-14C]sorbitol during a 24-hour incubation in unsupplemented medium. These studies conducted at the cellular level suggest that restoration of normal myo-inositol metabolism, polyol content, and Math Eq pump activity altered by hyperglycemic conditions occurs rapidly following normalization of glucose concentration.
Details
- Title: Subtitle
- Reversal of hyperglycemic-induced defects in myo-inositol metabolism and Na+/K+ pump activity in cultured neuroblastoma cells by normalizing glucose levels
- Creators
- Mark A Yorek - Veterans administration medical cent., dep. internal medicine, Iowa City IA, United StatesJoyce A Dunlap - Veterans administration medical cent., dep. internal medicine, Iowa City IA, United StatesMark R Stefani - Veterans administration medical cent., dep. internal medicine, Iowa City IA, United StatesEric P Davidson - Veterans administration medical cent., dep. internal medicine, Iowa City IA, United States
- Resource Type
- Journal article
- Publication Details
- Metabolism, clinical and experimental, Vol.42(9), pp.1180-1189
- Publisher
- Elsevier
- DOI
- 10.1016/0026-0495(93)90278-V
- PMID
- 8412773
- ISSN
- 0026-0495
- eISSN
- 1532-8600
- Language
- English
- Date published
- 1993
- Academic Unit
- Fraternal Order of Eagles Diabetes Research Center; Endocrinology and Metabolism; Internal Medicine
- Record Identifier
- 9984094638902771
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