PhTx4, a new class of toxins from Phoneutria nigriventer spider venom, inhibits the glutamate uptake in rat brain synaptosomes.
We report the characterization of a new class of glutamate uptake inhibitors isolated from Phoneutria nigriventer venom. Glutamate transport activity was assayed in rat cerebrocortical synaptosomes by using [(3)H]-L-glutamate. PhTx4 inhibited glutamate uptake in a dose dependent manner. The IC(50) value obtained was 2.35+/-0.9 microg/ml which is in the observed range reported for glutamate uptake blockers. Tx4-7, one of PhTx4 toxins, showed the strongest inhibitory activity (50.3+/-0.69%, n=3).
Departamento de Fisiologia e Biofísica, ICB, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, 31270-901, Belo Horizonte-MG, Brazil.
R A
RA
Mafra
S G
SG
Figueiredo
C R
CR
Diniz
M N
MN
Cordeiro
J D
JD
Cruz
M E
ME
De Lima
D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D018698:Glutamic Acid / Q000378:metabolism*; D009479:Neuropeptides / Q000633:toxicity*; D009498:Neurotoxins / Q000633:toxicity*; D051381:Rats; D017208:Rats, Wistar; D013111:Spider Venoms / Q000737:chemistry* / Q000145:classification; D013574:Synaptosomes / Q000187:drug effects* / Q000378:metabolism
D009479:Neuropeptides; D009498:Neurotoxins; D013111:Spider Venoms; D018698:Glutamic Acid