title: Change in intracellular pH in Tetrahymena pyriformis GL in relation to the toxicity level of the lonophorous antibiotic nigericin.
abstract: Nigericin, a carboxylic poly ether antibiotic, is toxic towards Tetrahymena pyriformis GL [1, 7, 12, 13]. Nigericin transports K(+) across biological membranes along the gradient. This transport is generally equilibrated by an influx of H(+) ions. The toxicity of nigericin (at low 10 mg · l(-1) and high 30 mg · l(-1) levels) was studied by measuring the intracellular pH of Tetrahymena pyriformis GL by means of two labelled molecules: (14)C-DMO and (3)H-inulin. This measurement of pHi requires prior knowledge of the number of cells and their volume. The results reveal a correlation of the toxicity of nigericin, acidification of the intracellular environment and increase in cell volume leading to the return of pHi to control values.
authors.affiliation: Laboratoire de Zoologie et Protistologie, U.A. 138 du CNRS, Université Blaise Pascal, Clermont-Ferrand, Aubière, France.
authors.forename: M
authors.initials: M
authors.lastname: Bamdad
authors.forename: C A
authors.initials: CA
authors.lastname: Grolière
authors.forename: J
authors.initials: J
authors.lastname: Dupy-Blanc
authors.forename: L
authors.initials: L
authors.lastname: David
authors.forename: M
authors.initials: M
authors.lastname: Gendraud