Comparative study of glutamate mediated gamma-aminobutyric acid release from nitric oxide synthase and tyrosine hydroxylase immunoreactive cells of the Cebus apella retina.
The effects of excitatory amino acids (EAAs) upon transporter-mediated gamma-aminobutyric acid (GABA) release were investigated in cells containing tyrosine hydroxylase (TH) or nitric oxide synthase (NOS) in retina of the primate Cebus apella. Retinas were treated in vitro with 50 microM Kainate (KA) or 5 mM L-Glutamate (L-Glu), for 30 min at 37 degrees C, in an Mg2+-free Locke's solution with or without Ca2+. The effects of EAAs were measured immunocytochemically by determining the GABA content in TH or NOS-immunoreactive cells in the inner retina, after stimulation. L-Glu and KA induced a Ca2+-independent GABA release from most GABA-immunoreactive cells of the inner retina. Double label experiments indicated that this release occurs in NOS+/GABA+ cells, but not in TH+/GABA+ cells suggesting that these cell subpopulations may be differentiated in some functional aspects.
Departamento de Fisiologia e Farmacologia, UFPE, PE, Recife, Brazil
B L
BL
Andrade da Costa
F G
FG
de Mello
J N
JN
Hokoç
D000818:Animals; D002428:Cebus; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D018698:Glutamic Acid / Q000494:pharmacology*; D007608:Kainic Acid / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000187:drug effects* / Q000378:metabolism; D012160:Retina / Q000187:drug effects* / Q000378:metabolism; D014446:Tyrosine 3-Monooxygenase / Q000187:drug effects* / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000187:drug effects* / Q000378:metabolism
D018690:Excitatory Amino Acid Agonists; D018698:Glutamic Acid; D005680:gamma-Aminobutyric Acid; D019001:Nitric Oxide Synthase; D014446:Tyrosine 3-Monooxygenase; D007608:Kainic Acid