Homocysteine alters glutamate uptake and Na(+),K (+)-ATPase activity and oxidative status in rats hippocampus: protection by vitamin C.
Summary of "Homocysteine alters glutamate uptake and Na(+),K (+)-ATPase activity and oxidative status in rats hippocampus: protection by vitamin C."
In the present study we investigate the effect of homocysteine on glutamate uptake, Na(+),K(+)-ATPase, enzymatic antioxidant defenses, as well as reactive species levels in hippocampus of rats. The influence of vitamin C, a classic antioxidant, on the effects elicited by homocysteine was also tested. Results showed that chronic hyperhomocysteinemia decreased glutamate uptake and the activities of Na(+),K(+)-ATPase, catalase and superoxide dismutase in hippocampus of rats. Reactive species levels were increased by chronic homocysteine administration. Concomitant administration of vitamin C significantly prevented these alterations caused by homocysteine. According to our results, it seems possible to suggest that the reduction in glutamate uptake and Na(+),K(+)-ATPase activity may be mediated by oxidative stress, since vitamin C prevented these effects. We suggest that the administration of antioxidants should be considered as an adjuvant therapy to specific diet in homocystinuria.
Affiliation
Laboratório de Neuroproteção e Doença Metabólica, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-Anexo, CEP 90035-003, Porto Alegre, RS, Brazil.
Journal Details
This article was published in the following journal.
Name: Metabolic brain disease
ISSN: 1573-7365
Pages:
Links
- PubMed Source: http://www.ncbi.nlm.nih.gov/pubmed/21287399
- DOI: http://dx.doi.org/10.1007/s11011-011-9232-3
Medical and Biotech [MESH] Definitions
Neurotransmitter Uptake Inhibitors
Drugs that inhibit the transport of neurotransmitters into axon terminals or into storage vesicles within terminals. For many transmitters, uptake determines the time course of transmitter action so inhibiting uptake prolongs the activity of the transmitter. Blocking uptake may also deplete available transmitter stores. Many clinically important drugs are uptake inhibitors although the indirect reactions of the brain rather than the acute block of uptake itself is often responsible for the therapeutic effects.
Glutamate Plasma Membrane Transport Proteins
A family of plasma membrane neurotransmitter transporter proteins that couple the uptake of GLUTAMATE with the import of SODIUM ions and PROTONS and the export of POTASSIUM ions. In the CENTRAL NERVOUS SYSTEM they regulate neurotransmission through synaptic reuptake of the excitatory neurotransmitter glutamate. Outside the central nervous system they function as signal mediators and regulators of glutamate metabolism.
Ca(2+) Mg(2+)-atpase
An enzyme that catalyzes the hydrolysis of ATP and is activated by millimolar concentrations of either Ca(2+) or Mg(2+). Unlike CA(2+)-TRANSPORTING ATPASE it does not require the second divalent cation for its activity, and is not sensitive to orthovanadate. (Prog Biophys Mol Biol 1988;52(1):1). A subgroup of EC 3.6.1.3.
Homocysteine S-methyltransferase
An enzyme that catalyzes the demethylation of L-homocysteine to L-METHIONINE.
Metabolic Equivalent
A measurement of OXYGEN uptake in a sitting, resting person (resting oxygen consumption), varying with age, sex, race, and other factors. In normal adult men, one MET is approximately 3.5 ml O2/kg/min of body weight. Oxygen uptake during activities or work can be measured in METs which can be use to determine health status and exercise prescription.
PubMed Articles
Status epilepticus-induced hippocampal neuronal loss is mainly associated with excitotoxicity induced by increased levels of extracellular glutamate which is normally neutralized by high-affinity upta...
This study investigated the effects of acute and chronic hyperprolinemia on glutamate uptake, as well as some mechanisms underlying the proline effects on glutamatergic system in rat cerebral cortex....
Na+,K+-ATPase is a membrane protein which plays a key role in the maintenance of ion homeostasis that is necessary to neuronal excitability, secondary transport and neurotransmitter uptake. Mild hyper...
This study was designed to investigate the protective effects of the combination of guanosine and 2 organoselenium compounds (ebselen and diphenyl diselenide) against glutamate-induced oxidative stres...
Schizophrenia is a debilitating mental disorder with a global prevalence of 1% and its etiology remains poorly understood. In the current study we investigated the influence of antipsychotic drugs on...
Clinical Trials
Biomarkers of Oxidative Stress in LOOK AHEAD - Ancillary to LOOK AHEAD
To determine how weight loss achieved by intensive lifestyle intervention including diet and exercise alters lipoprotein oxidation/oxidative stress and antioxidant status in overweight dia...
Quantitative in Vivo Biomarkers of Oxidative Stress in Diabetes
Oxidative stress has been implicated in the development and complications of diabetes. Hyperglycemia and insulin resistance or insufficiency in diabetes can cause oxidative stress by exces...
Recently literature revealed facts, that show H+/K+ ATPase expression is not limited tot he stomach. H+/K+ ATPase was also found in smooth muscle cells and in other tissues (McCabe, R.D. e...
The activity of the sympathetic nervous system seems to influence the uptake (and handling) of glucose by the skeletal muscle of the forearm. Conditions in which sympathetic activity is in...
Elevation of plasma homocysteine has been recognized as one of the risk factors of atherosclerotic disease. The objectives of this study are: (1) to investigate the level of plasma homocys...
