Expression of a glutamate-activated chloride current in Xenopus oocytes injected with Caenorhabditis elegans RNA: evidence for modulation by avermectin.
Brain Res Mol Brain Res
; 15(3-4): 339-48, 1992 Oct.
Article
en En
| MEDLINE
| ID: mdl-1279355
ABSTRACT
Membrane currents were recorded from Xenopus laevis oocytes injected with C. elegans poly(A)+ RNA. In such oocytes glutamate activated an inward membrane current that desensitized in the continued presence of glutamate. Glutamate-receptor agonists quisqualate, kainate, and N-methyl-D-aspartate were inactive. The reversal potential of the glutamate-sensitive current was -22 mV, and exhibited a strong dependence on external chloride with a 48 mV change for a 10-fold change in chloride. The chloride channel blockers flufenamate and picrotoxin inhibited the glutamate-sensitive current. Ibotenate, a structural analog of glutamate, also activated a picrotoxin-sensitive chloride current. Ibotenate was inactive when current was partially desensitized with glutamate, and the responses to low concentrations of glutamate and ibotenate were additive. The anthelmintic/insecticide compound avermectin directly activated the glutamate-sensitive current. In addition, avermectin increased the response to submaximal concentrations of glutamate, shifted the glutamate concentration-response curve to lower concentrations, and slowed the desensitization of glutamate-sensitive current. We propose that the glutamate-sensitive chloride current and the avermectin-sensitive chloride current are mediated via the same channel.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Oocitos
/
Poli A
/
ARN
/
Cloruros
/
Caenorhabditis elegans
/
Glutamatos
/
Proteínas de la Membrana
Límite:
Animals
Idioma:
En
Revista:
Brain Res Mol Brain Res
Asunto de la revista:
BIOLOGIA MOLECULAR
/
CEREBRO
Año:
1992
Tipo del documento:
Article