Possible Interaction: Gamma-Aminobutyric Acid and Proline

“The substrate specificity of the high-affinity transporter was further studied and Gly-Sar, Leucine, gaboxadol, sarcosine, lysine, betaine, 5-hydroxythryptophan, proline and glycine reduced the GABA uptake to approximately 44-70% of the GABA uptake in the absence of inhibitor.”

“The concentrations of proline increased together with γ-aminobutyrate , arginine, asparagine, cystine, glutamate, glutamine, hydroxylysine, sarcosine, serine, and taurine.”

“Superfusion of GABA resulted in a concentration-dependent reduction in input resistance in 67.5% of the neurons in the PBN (73.1% of the DL- , 62.5% of the DM-, 66.7% of the VM-neurons).”

“Furthermore, homo‐β‐proline also displaced GABA from its receptor with an IC50 value of 0.3 μM. The cis‐4‐hydroxynipecotic acid analogues, cis‐ and trans‐4‐mercaptonipecotic acid, had no inhibitory effect on glial or neuronal GABA uptake.”

“IC50 values for GABA uptake into glial cells and brain cortex “prisms” were 20 and 75 μM, … for GABA uptake into cultured neurons was 10 μM. A kinetic analysis of the action of homo‐β‐proline on GABA uptake into cultured astrocytes … acts as a competitive inhibitor of GABA ….”

“This mechanism of action strongly suggests that homo‐β‐proline interacts with the GABA carriers.”

“During differentiation the taurine, glutamic acid, GABA , glutamine, aspartic acid, glycine arginine, methionine and histidine levels increase while proline.”

“… GABA and N for … contents in grains, proline content in leaves, GABA content in leaves at 15 d AH and maturity stage (MS), Δ1‐pyrroline‐5‐carboxylic acid (P5C) … 15 d AH, and Δ1‐pyrroline‐5‐carboxylate synthase (P5CS), PDH, and OAT activities in leaves at MS was noted.”

“ GABA priming significantly reduced Na+ concentrations, proline , free radical and malonaldehyde and also significantly increased K+ concentration under the stress condition.”

“ GABA enhanced the accumulation of amino acids (GABA, glycine, valine, proline , 5-oxoproline, serine, threonine, aspartic acid and glutamic acid) and organic acids (malic acid, lactic acid, gluconic acid, malonic acid and ribonic acid).”

“The resultS showed that the antioxidant enzyme activity, electrolyte leakage, MDA and proline content were significantly reduced by GABA treatments.”

“ GABA treatment significantly enhanced the accumulation of endogenous GABA and proline , which resulted from the increased activities of glutamate decarboxylase, Δ(1)-pyrroline-5-carboxylate synthetase, and ornithine δ-aminotransferase and decreased proline dehydrogenase activity.”