Effect of nitric oxide donors on GABA uptake by rat brain synaptosomes.
The effect of nitric oxide donors and L-arginine on the uptake of GABA was studied in synaptosomes purified from rat brain. The neurotransmitter uptake was significantly reduced by S-nitrosoacetylpenicillamine and by sodium nitroprusside, although in this case to a lesser extent. A slight inhibitory effect was found preincubating rat brain synaptosomes with 1 mM L-arginine as well. The S-nitrosoacetylpenicillamine effect gradually disappeared with decomposition of the substance by exposure to light. The nitric oxide effect appears to be mainly due to a decrease in the V for synaptosomal GABA uptake and seems to be related to a partial collapse of nerve endings ionic gradients. Functionally, it could result over time in a reduced availability of GABA at the synapses involved.
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Centro di Neurofisiologia Cerebrale, C.N.R., Genova, Italy.
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D000818:Animals; D001120:Arginine / Q000494:pharmacology; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism / Q000494:pharmacology*; D019335:Nitroarginine / Q000494:pharmacology; D009599:Nitroprusside / Q000494:pharmacology; D010396:Penicillamine / Q000031:analogs & derivatives / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D026423:S-Nitroso-N-Acetylpenicillamine; D013574:Synaptosomes / Q000187:drug effects* / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000187:drug effects* / Q000378:metabolism
D009599:Nitroprusside; D019335:Nitroarginine; D009569:Nitric Oxide; D005680:gamma-Aminobutyric Acid; D026423:S-Nitroso-N-Acetylpenicillamine; D001120:Arginine; D010396:Penicillamine