Open AccessEffects of amiodarone on K + , internal pH and Ca 2+ homeostasis in Saccharomyces cerevisiae
Author(s) -
Peña Antonio,
Calahorra Martha,
Michel Bertha,
Ramírez Jorge,
Sánchez Norma Silvia
Publication year - 2009
Publication title -
fems yeast research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.991
H-Index - 92
eISSN - 1567-1364
pISSN - 1567-1356
DOI - 10.1111/j.1567-1364.2009.00538.x
Subject(s) - efflux , saccharomyces cerevisiae , membrane , yeast , amiodarone , membrane potential , biology , biophysics , biochemistry , homeostasis , cell membrane , metabolism , medicine , microbiology and biotechnology , atrial fibrillation
In this study, amiodarone, at very low concentrations, produced a clear efflux of K + . Increasing concentrations also produced an influx of protons, resulting in an increase of the external pH and a decrease of the internal pH. The K + efflux resulted in an increased plasma membrane potential difference, responsible for the entrance of Ca 2+ and H + , the efflux of anions and the subsequent changes resulting from the increased cytoplasmic Ca 2+ concentration, as well as the decreased internal pH. The Δ tok1 and Δ nha1 mutations resulted in a smaller effect of amiodarone, and Δ trk1 and Δ trk2 showed a higher increase of the plasma membrane potential. Higher concentrations of amiodarone also produced full inhibition of respiration, insensitive to uncouplers and a partial inhibition of fermentation. This phenomenon appears to be common to a large series of cationic molecules that can produce the efflux of K + , through the reduction of the negative surface charge of the cell membrane, and the concentration of this cation directly available to the monovalent cation carriers, and/or producing a disorganization of the membrane and altering the functioning of the carriers, probably not only in yeast.