Possible Interaction: Alanine and Ammonia

“Furthermore, after L-alanine oral load , significantly higher ammonia plasma levels were observed in cirrhotics than in controls.”

“G + A prevented the muscle ammonia increase by RT, whereas ALA and DIP augmented ammonia and glycogen concentrations in muscle.”

“In controls, ammonia increased 12.8-fold while glutamate and aspartate decreased by approximately 40% and glutamine and alanine raised by 37% and 93%, respectively; in hyperammonemic rats ammonia increased 6.9-fold while glutamate, glutamine and alanine were not significantly affected.”

“Primarily, ammonia stimulated ureogenesis hence accelerating the deamination of alanine which led to the increased formation of pyruvate, lactate and glucose.”

“ Alanine , leucine, and glutamine significantly (P less than 0.01) increased ammonia release into mesenteric venous blood by 37, 42, and 106%, respectively, whereas threonine, serine, and glycine had no effect.”

“When ammonia concentration was high, alanine concentration rose rapidly suggesting that alanine might serve as a storage depot for ammonia and also might provide an additional route for transport of glucose precursors (i.e., pyruvate) from the rumen.”

“ Alanine inhibited uncompetitively with respect to NADH (Ki=1.6 mM) and noncompetitively with respect to ammonia (Ki=2.0 mM) and pyruvate (Ki=3.0 mM).”

“In addition, the alanine mutant enzyme that is almost inactive in the deamination but significantly active in the amination was greatly stimulated by exogenously added ammonia , suggesting that proper binding of the substrate alpha-carboxyl group at Lys-68 is essential for catalysis.”

“In contrast, the inhibition of cytosolically generated alanine was less dramatic and averaged only 20% of the effect on ammonia production.”

“Glutamine, glutamate, asparagine, aspartate, alanine , and serine levels decline concomitantly with ammonia accumulation.”