Possible Interaction: Glycine and Progesterone

“It was hypothesized that the fall in uterine glycine may be responsible for the high levels of this amino acid in luminal fluids of the genital tract under progesterone stimulus.”

“ Progesterone , given to non-pregnant women, caused a fall in mean plasma glycine.”

“On the basis … that during progesterone treatment only … of glycine , threonine, cystine and serine were lower fasting and postprandially than they were fasting on control days, it has been suggested … of these four compounds, or a combination of several of them, may be critical in regulating peripheral protein catabolism.”

“The most marked effect of progesterone was on oviducal amino acid concentrations, with a twofold increase in glycine , whereas in the uterus only valine was increased.”

“Thus, progesterone can increase the synaptic miniature release of glycine and this effect appears to be indirect, resulting from its metabolism into 5α‐reduced derivatives, in particular into allopregnanolone.”

“In 16-day-old rats EP induced an increase in the concentrations of aspartate, glutamate, and glycine in the anterior and preoptic hypothalamic areas and in the medial basal hypothalamus, the excitatory amino acids involved in NMDA neurotransmission.”

“ Progesterone , desoxycorticosterone (DOC), diethylstilbestrol, and 5 β-H steroids such as etiocholanolone, considerably accelerated the leakage of anions, glucose, and glycine into the surrounding medium, as did Triton and streptolysin.”