Possible Interaction: Gamma-Aminobutyric Acid and Progesterone

“Estrogen augments N-methyl-D-aspartate-mediated glutamate receptor activity via reduction of GABA production, while progesterone enhances GABA neurotransmission and inhibits neural excitement.”

“The maximal stimulatory effect was observed with 1.25 mumol/L GABA, and the AR … with further increase of GABA concentration to 10 mumol/L. Exposure of preincubated spermatozoa to GABA in … progesterone resulted in a higher proportion of the AR … with that obtained with each agonist applied alone.”

“Exposure of preincubated spermatozoa to GABA and progesterone together resulted in a higher proportion of acrosome reactions than when each agonist was used alone.”

“ Progesterone , through conversion to its neurosteroid metabolite 3 alpha-OH DHP, potentiates GABA responses of cerebellar Purkinje cells.”

“Finally, the latter was attributed to the large (up to 80 nM) TRIL-induced increase of brain 3 alpha,21-dihydroxy-5 alpha-pregnan-20-one, which like TH PROG potentiates inhibitory gamma-aminobutyric acid (GABA)ergic neurotransmission.”

“ Progesterone , through its neurosteroid derivative allopregnanolone, increases γ-aminobutyric acid type-A receptor (GABAR)-mediated inhibition in the brain and keeps seizures under control.”

“Allopregnanolone and its stereoisomer pregnanolone (together termed ALLO) are metabolites of progesterone that positively and allosterically modulate GABA effects at GABAA receptors, thereby reducing anxiety and depression.”

“ Progesterone and its metabolites have also been implicated in the allosteric regulation of several unrelated receptors, such as gamma-aminobutyric acid type A , oxytocin and sigma(1) receptors.”

“Intermediate steps, such as opioids and g-aminobutyric acid (GABA), may be involved in producing this effect of progesterone.”

“The discharges of GnRH neurons triggered by excitatory amino acids are modulated by estradiol, while the inhibitory effect of progesterone is mediated by GABA and beta-endorphin which cause hyperpolarization of the GnRH neurons and consequently a reduced pulse frequency.”