Effects of KCl-induced depolarization on the GABA concentration in the corpus striatum and in the substantia nigra.
The effects of potassium ion depolarization on the concentration, the synthesis and the utilization of GABA as well as the effects on the concentrations of glutamine, dopamine (DA) and DOPAC in the substantia nigra and in the corpus striatum of the rat were investigated. An intranigral KCl injection did not influence the GABA concentration or the synthesis and utilization of GABA in the substantia nigra. Following an intrastriatal KCl injection the GABA concentration increased and the glutamine concentration decreased in the corpus striatum. A marked increase in the DNA concentration in the corpus striatum was seen following an intranigral KCl injection, whereas the DA concentration decreased and the DOPAC concentration increased following an intrastriatal KCl injection. It is concluded that the GABA in the substantia nigra and in the corpus striatum is affected differently by potassium ions, perhaps due to the different cellular localization of GABA in the two structures. The increase of GABA in the corpus striatum was accompanied by a decreased glutamine concentration indicating that glutamine might be a precursor of GABA.
D015102:3,4-Dihydroxyphenylacetic Acid / Q000032:analysis; D000480:Alkynes; D000614:Aminocaproates / Q000494:pharmacology; D000818:Animals; D003342:Corpus Striatum / Q000032:analysis*; D004298:Dopamine / Q000032:analysis; D005973:Glutamine / Q000032:analysis; D008297:Male; D011189:Potassium Chloride / Q000494:pharmacology*; D011736:Pyridoxine / Q000031:analogs & derivatives / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D013378:Substantia Nigra / Q000032:analysis*; D005680:gamma-Aminobutyric Acid / Q000032:analysis*
D000480:Alkynes; D000614:Aminocaproates; D005973:Glutamine; D015102:3,4-Dihydroxyphenylacetic Acid; D005680:gamma-Aminobutyric Acid; C013785:4-amino-5-hexynoic acid; C004675:4-deoxypyridoxine; D011189:Potassium Chloride; D011736:Pyridoxine; D004298:Dopamine