Effect of protein kinase C activators on the uptake of GABA by rat brain synaptosomes.
Synaptosomes were prepared from rat brain by a discontinuous Ficoll gradient method and used for studying the uptake of labelled GABA. Two GABA uptake components were evidenced, a high (Km = 3.13 microM) and a low (Km = 92.4 microM) affinity one. Preincubation of synaptosomes with two different activators of protein kinase C, phorbol 12, 13-diacetate (PDAc) and oleyl-acetyl glycerol (OAG), resulted in a change of GABA uptake. In particular, the low affinity component increased its Vmax by 58-74%, with no change in the Km. No statistically significant modification was detected for the high affinity component.
Cupello
A
A
Centro di Neurofisiologia, C.N.R., Genova, Italy.
Gasparetto
B
B
Mainardi
P
P
Vignolo
L
L
Robello
M
M
D000818:Animals; D001921:Brain / Q000378:metabolism*; D046508:Culture Techniques; D004075:Diglycerides / Q000494:pharmacology*; D008297:Male; D010703:Phorbol Esters / Q000494:pharmacology*; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013574:Synaptosomes / Q000187:drug effects*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D004075:Diglycerides; D010703:Phorbol Esters; C008874:phorbol-12,13-diacetate; D005680:gamma-Aminobutyric Acid; C038237:1-oleoyl-2-acetylglycerol; D011493:Protein Kinase C