Effect of DHEA glutamate release from synaptosomes of rats at different ages.
Dehydroepiandrosterone (DHEA) exerts multiple effects in the central nervous system. Most of them seem to be mediated through their nongenomic actions on neurotransmitter receptors, and these actions occur within seconds or milliseconds. DHEA increases neuronal excitability, enhances neuronal plasticity, and has neuroprotective properties. By investigating glutamate release from synaptosomes of rats at different ages (from 17 days to 12 months), we observed that (i) there is an increase in basal and K(+)-stimulated L-[3H] glutamate release in rats at 12 months old, when compared to other ages; and (ii) there is an inhibitory effect of DHEA on basal L-[3H] glutamate release in 12 months old. This inhibitory effect of DHEA could be related to its reported protective role against excitotoxicity caused by overstimulation of the glutamatergic system and ageing.
Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil. flrl@terra.com.br
Francisco L R
FL
Lhullier
Neusa G
NG
Riera
Rafael
R
Nicolaidis
Débora
D
Junqueira
Kelly C S
KC
Dahm
Franciele
F
Cipriani
Ana M
AM
Brusque
Diogo O
DO
Souza
D000375:Aging / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000378:metabolism*; D003687:Dehydroepiandrosterone / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology*; D018698:Glutamic Acid / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D009994:Osmolar Concentration; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013574:Synaptosomes / Q000378:metabolism*
D018691:Excitatory Amino Acid Antagonists; D018698:Glutamic Acid; D003687:Dehydroepiandrosterone; D011188:Potassium