Metabolic changes induced in rat hippocampal slices by norepinephrine.
The oxidative metabolic activity of restricted regions of hippocampal slices was assessed by a continuous measurement of the fluorescence of intramitochondrial nicotinamide-adenine dinucleotide (NADH). A large increase in NADH fluorescence was triggered by substituting the oxygen supply to the slice by nitrogen gas. A large and transient increase in NADH fluorescence was also produced by superfusion of the the slice with a high (50 mM) potassium-containing medium. Addition of norepinephrine (NE) to the superfusion medium caused a propranolol-inhibited increase in NADH fluorescence. Furthermore, ouabain, which inhibits the Na-K pump, blocked the effects of NE. An analog of cyclic adenosine monophosphate (cAMP), 8-bromo cAMP, mimicked the effect of NE. Finally, effects of NE could still be produced in a kainic acid-treated hippocampus, where most neurons were previously destroyed by the drug. It is suggested that NE activates a Na-K-ATPase, that this effect might be mediated by cAMP, and that these interrelations may underly the physiological action of NE in the brain.
D000818:Animals; D006624:Hippocampus / Q000187:drug effects* / Q000201:enzymology; D008297:Male; D008856:Microscopy, Fluorescence; D008928:Mitochondria / Q000201:enzymology; D009243:NAD / Q000378:metabolism; D009638:Norepinephrine / Q000494:pharmacology*; D010084:Oxidation-Reduction; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*
D009243:NAD; D011433:Propranolol; D000254:Sodium-Potassium-Exchanging ATPase; D009638:Norepinephrine