Possible Interaction: Gamma-Aminobutyric Acid and Insulin

“In 12 normal subjects, a single … dose of 5 or 10 g GABA , as compared to placebo, caused a significant (p less than 0.01) and dose-dependent (p less than 0.01) increase of plasma levels of immunoreactive insulin , C peptide and glucagon, without affecting plasma glucose concentration.”

“ GABA increased insulin production and reduced drug-induced apoptosis, and these actions were reversed by SIRT1 inhibitors.”

“It acts on gamma-aminobutyric acid type A and monoamine oxidase A or B receptor, enhances insulin sensitivity and also produces vasorelaxant effect.”

“Meanwhile, intranasal insulin increased GABA levels and the activities of hippocampal theta, which may affect the excitability of the hippocampus.”

“Conclusions: The results suggest that intake of GBR and GABA during pregnancy and lactation can influence the programming of genes in rat offspring, thereby enhancing insulin sensitivity.”

“At α2 and α4 containing forms, insulin could inhibit maximal GABA currents.”

“Submaximal GABA currents at all isoforms studied were inhibited by nanomolar concentrations of insulin.”

“In contrast, treating INS-1 cells with GABA (100μM) largely prevented the ethanol-induced reduction of insulin release.”

“Radioimmunoassay revealed that the secretion of C-peptide was enhanced by GABA , which was blocked by pre-incubating the cells with picrotoxin (50 µM, p<0.01) and insulin (1 µM, p<0.01), respectively.”

“b) In the second largest set of neurons (32-38%) insulin decreased the magnitude of GABA inhibitions when co-applied. (”

“ Insulin will significantly inhibit currents induced by EC(30-50) concentrations of GABA by about 38%.”

“It is likely then that insulin and GABA may interact, perhaps at the GABA(A) receptor.”

“Using a receptor isoform, alpha(1)beta(2)gamma(2s) that is the likely main neuronal GABA(A) isoform expressed recombinantly in Xenopus oocytes, insulin inhibits GABA-induced current when applied simultaneously with low concentrations of GABA.”