Uptake of amino acids by the parasitic, flagellated protist Trichomonas vaginalis

HPLC techniques have been applied to study amino acid uptake and release by Trichomonas vaginalis under a variety of conditions. Studies on the growth of T. vaginalis in complex media and the survival of the parasite in simple media, with and without amino acids and/or maltose, have shown that the growth or survival of T. vaginalis is better in the presence of maltose than when it is absent, and that greater amounts of amino acids are consumed by T. vaginalis in the absence of maltose. The results are consistent with several amino acids, notably arginine, threonine, leucine and methionine, being used by T. vaginalis as energy substrates. T. vaginalis released alanine and glycine into the culture media, the excretion being greater in the presence of maltose. These studies have provided new data on the uptake and release of amino acids by T. vaginalis and pave the way for detailed analysis of key enzymes and the regulation of the pathways involved.