Possible Interaction: Arachidonic Acid and Gamma-Aminobutyric Acid

“Whole-cell currents evoked by 10 microM GABA were inhibited in a concentration-dependent manner by arachidonic acid (0.1-100 microM).”

“Electrophysiologically it is found that the addition of AA (10 M) to GABAA receptors consisting of α3β2γ2S subunits leads to an approximately twofold increase in the whole-cell chloride ion current induced by a submaximal concentration of GABA.”

“Experiments on rats showed that, under conditions of global transient ischemia, a conjugate of GABA with arachidonic acid enhances the local cerebral blood flow due to a decrease in the vascular tone.”

“In guinea pig spermatozoa prelabelled with [14C]arachidonic acid or [14C]choline chloride, GABA stimulated a decrease in phosphatidylcholine (PC), and release of arachidonic acid and lysoPC, during exocytosis.”

“Prostaglandin synthase plus arachidonic acid significantly enhanced the ischemia-evoked release of all amino acids (aspartate 360 fold; glutamate 433 fold; glycine 6 fold; GABA 689 fold; phosphoethanolamine 69 fold) and increased the pre-ischemic levels of glutamate, glycine and phosphoethanolamine.”

“In fact, VGB at 25mM significantly (P<0.05) potentiated the contractile … AA 4.3x10(-5)M. Incubation of the same tissue with GABA at 13x10(-3) and 26x10(-… inhibited responses elicited by AA at 4.3x10(-5)M that was significant (….05) only with low concentration of GABA.”

“In this study, we found that AA (10 μM) increased the basal outflow (19 ± 4%) and the K+‐evoked release of [3H]GABA (38 ± 3%) from rat hippocampal synaptosomes.”

“These results show that exogenously added and endogenously produced AA increased basal outflow and K+‐evoked release of [3H]GABA from rat hippocampal synaptosomes.”

“ Arachidonic acid , which may be released via phospholipase A2, has been shown to inhibit several sodium-coupled uptake systems, including those for glycine and glutamate; also, the modulation of glutamate transporters by PKC, as well as the regulation by cAMP of GABA transporters, have been demonstrated.”

“Indeed, AA reduced the Na+-dependent uptake of endogenously released amino acids, which were labelled with traces of tritiated D-aspartate and GABA.”

“Therefore, AA possibly enhances the extracellular levels of aspartate, glutamate and GABA by inhibiting the uptake of these amino acids and not their efflux.”

“Arachidonic acid AA ) also reduced the IGABA in a manner similar to DHA.”

“DHA, as well as AA , may play an important role in modulating neuronal excitability by reducing the IGABA and Igly, and potentiating N-methyl-D-aspartate receptor-mediated responses in the SN.”