[Effect of ionic composition of incubation medium on inhibition by levorin of amino acid transfer in Candida albicans].

It was demonstrated that K+ and Na+ concentrations in C. albicans cells cultivated on an aerated enriched complex medium do not practically depend on their concentration ratios in the medium. The effect of levorin on the ionic composition of the cells, on the contrary, strongly depends on the composition of the medium. In a Na-containing medium with levorin the bulk of intracellular potassium is substituted by sodium, while in a "potassium" medium no redistribution of the monovalent cations in the cells occurs. The transport of neutral amino acids with a short carbohydrate radical (e. g. glycine, alanine) is largely inhibited by levorin irrespective of the intra- and extracellular concentrations of the movement cations. The inhibition of transport of amino acids with a long carbohydrate radical (e. g. leucine, phenylalanine) by levorin is possibly mediated by its effect on the intracellular concentration of monovalent cations, since in "potassium" medium it is either insignificant or altogether absent. The transfer of neutral amino acids differing in the length of the carbohydrate radical of C. albicans by various systems is discussed.