Effects of polyene macrolides on the membrane potential of resting and activated human leukocytes

Membrane potential changes in human polymorphonuclear leukocytes have been studied by monitoring the fluorescence signal of a carbocyanine probe in the presence of calcium ionophore A23187, chemotactic tripeptide f-met-leu-phe, and polyene macrolides. Reduction of the signals triggered by the ionophore and the tripeptide, inhibition of the respiratory burst, and changes in the Na+ influx into the cell seem to be the dominant effect of the polyenes. Polyene-induced depolarization does not correlate with the inhibition of the respiratory burst.