Magainins affect respiratory control, membrane potential and motility of hamster spermatozoa

Abstract

The hypothesis was tested that the magainin peptides, known to compromise bacterial and mitochondrial energetics, are highly active against spermatozoa. A mixture of magainin A and PGLa (1:1) caused a 50% reduction in motility of hamstet spermatozoa at 4 μg/ml total peptide concentration, All motility was lost at 8 μ/ml. At this concentration, respiratory control was released and respiration in the presence of uncoupler was inhibited. Uptake or the lipophilic cation tetraphenyl phosphonium was largely abolished by addition or magainin A and PGLa at this concentration, indicative of a decrease in the mitochondrial membrane potential. Magainin A and PGLa showed synergism with respect to release of respiratory control.