title: Effects of glucose on calcium channels in neural cells.
abstract: Hyperglycemia has been reported to alter outcome following experimental and clinical cerebral ischemia, but the mechanisms involved are incompletely understood. Since glucose influences the function of dihydropyridine-sensitive, voltage-gated Ca2+ channels in some non-neural cells, and since cellular Ca2+ overload has been implicated in the pathogenesis of ischemic neuronal injury, we examined whether glucose regulates Ca2+ channel function in a cultured neural cell line. Physiologic concentrations of glucose had no effect on free intracellular Ca2+ levels in PC12 cells, but 4-fold elevation of glucose above physiologic levels reduced the dihydropyridine-sensitive, depolarization-induced increase in Ca2+. This effect would not account for exacerbation of ischemic brain injury by hyperglycemia, but may contribute to attenuation of ischemic injury by glucose in certain settings.
authors.affiliation: Department of Neurology, University of California, San Francisco.
authors.forename: J
authors.initials: J
authors.lastname: Chan
authors.forename: D A
authors.initials: DA
authors.lastname: Greenberg
mesh_terms: D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; D000310:Adrenal Gland Neoplasms / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000187:drug effects*; D016257:Fura-2; D005947:Glucose / Q000494:pharmacology*; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D010673:Pheochromocytoma / Q000378:metabolism; D051381:Rats; D014407:Tumor Cells, Cultured
chemical_list: D015220:Calcium Channels; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; D005947:Glucose; D002118:Calcium; D016257:Fura-2