Metabolic properties of nerve endings isolated from rat brain
- 1 November 1979
- journal article
- research article
- Published by Wiley in Acta Physiologica Scandinavica
- Vol. 107 (3), 205-212
- https://doi.org/10.1111/j.1748-1716.1979.tb06464.x
Abstract
Energy metabolism was studied in nerve endings isolated from 3 wk old rat brain. Concentrations of glycogen, glucose, ATP, phosphocreatine and lactate were lower in synaptosomes than in the intact brain. The consumption of these endogenous substrates, the ability to generate high-energy phosphate, and the production of ammonia were determined in aerobic and anerobic conditions. Unlike nerve tissue in general, synaptosomes preferentially utilized endogenous ATP and phosphocreatine stores which, on incubation in the absence of exogenous substrates, were emptied long before glycogen stores were exhausted. The optimal medium for respiratory studies had electrolyte concentrations equal to the extracellular fluid. The synaptosomes had an endogenous respiration rate of 6.3 nmol O2 mg protein min, measured with an O2 electrode, and it probably reflects consumption of their glycogen stores. Glucose usually had no effect on the respiration rate of synaptosomes, but sometimes increased it slightly. After incubation in the presence of arsenate synaptosomes showed an increase in respiration when glucose was added. ADP, when added with glucose, also stimulated respiration. Pyruvate and succinate always increased respiration, succinate usually having the stronger effect. Isolated nerve endings are metabolically intact, which justifies their use in research on neurotransmission. Synaptic transmission does not seem primarily to depend on the availability of glucose but rather on local stores of high-energy phosphate compounds.Keywords
This publication has 17 references indexed in Scilit:
- GLUTAMINE—A MAJOR SUBSTRATE FOR NERVE ENDINGSJournal of Neurochemistry, 1978
- Energy utilization in the induced release of γ-aminobutyric acid from synaptosomesBrain Research, 1978
- 5′‐ADENINE MONONUCLEOTIDES TN SYNAPTOSOMAL PREPARATIONS FROM GUINEA PIG NEOCORTEX: THEIR CHANGE ON INCUBATION, SUPERFUSION AND STIMULATIONJournal of Neurochemistry, 1976
- Development of Glucose Oxidation in Isolated Nerve EndingsNature, 1973
- CATION MODULATION OF SYNAPTOSOMAL RESPIRATIONJournal of Neurochemistry, 1972
- RELATIONSHIPS BETWEEN ENERGY RESERVES AND FUNCTION IN RAT SUPERIOR CERVICAL GANGLION1Journal of Neurochemistry, 1969
- RESPIRATION IN VITRO OF SYNAPTOSOMES FROM MAMMALIAN CEREBRAL CORTEXJournal of Neurochemistry, 1969
- GLYCOGEN, AMMONIA AND RELATED METABOLITES IN THE BRAIN DURING SEIZURES EVOKED BY METHIONINE SULPHOXIMINE1Journal of Neurochemistry, 1969
- THE EFFECT OF DEPRIVATION OF GLUCOSE ON THE ULTRASTRUCTURE AND FUNCTION OF THE SUPERIOR CERVICAL GANGLION OF THE RAT IN VITROThe Journal of cell biology, 1966
- BIOCHEMICAL STUDIES ON MITOCHONDRIA AND OTHER CYTOPLASMIC FRACTIONS OF DEVELOPING RAT BRAINJournal of Neurochemistry, 1964