Effect of gamma-aminobutyric acid on the carnitine metabolism in neural cells.
Isolated rat cerebral cortex cells were able to accumulate L-carnitine and this process was competitively inhibited by 1 mM gamma-aminobutyric acid (GABA) with a shift of Km from 7.8 +/- 1.9 mM to 14.6 +/- 4.0 mM. Addition of GABA also affected distribution of carnitine derivatives. The decrease of acetylcarnitine level by 1.6 fold was correlated with the inhibition of carnitine acetyltransferase (1.77 times). A postulated involvement of this enzyme in delivering acetyl moieties for acetylcholine synthesis would suggest a negative feedback between GABA and the level of acetylcholine.
Wawrzeńczyk
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A
Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warszawa.
Nałecz
K A
KA
Nałecz
M J
MJ
D000108:Acetylcarnitine / Q000378:metabolism; D000109:Acetylcholine / Q000096:biosynthesis; D000818:Animals; D001667:Binding, Competitive; D002331:Carnitine / Q000378:metabolism*; D002332:Carnitine O-Acetyltransferase / Q000037:antagonists & inhibitors; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism*; D005246:Feedback; D007700:Kinetics; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology*
D005680:gamma-Aminobutyric Acid; D000108:Acetylcarnitine; D002332:Carnitine O-Acetyltransferase; D000109:Acetylcholine; D002331:Carnitine