title: Characterization of Trichomonas vaginalis haemolysis.
abstract: The haemolytic activity of live Trichomonas vaginalis organisms was investigated. Optimal haemolysis of human erythrocytes was observed at a parasite to erythrocyte ratio of 1:5 during a 2 h incubation period. No haemolytic activity was detected in concentrated culture supernatants after overnight growth of trichomonads or when parasites were separated from erythrocytes by a 3 microns filter, suggesting a contact-dependent mechanism for haemolysis. The haemolytic activity was temperature-dependent and maximal haemolysis occurred at 37 degrees C. Treatment of trichomonads with metronidazole reduced levels of haemolysis by greater than 50%. Maximal haemolysis occurred at the pH range of the vagina during trichomoniasis. N-alpha-tosyl-L-lysyl-chloromethyl ketone and iodoacetamide, inhibitors of trichomonad cysteine proteinases, reduced the haemolytic activity of live parasites.
authors: Department of Microbiology, University of Texas Health Science Center, San Antonio 78284-7758.
authors: D C
authors: DC
authors: Dailey
authors: T H
authors: TH
authors: Chang
authors: J F
authors: JF
authors: Alderete
mesh_terms: D000818:Animals; D002118:Calcium / Q000494:pharmacology; D006461:Hemolysis / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007460:Iodoacetamide / Q000494:pharmacology; D008274:Magnesium / Q000494:pharmacology; D008795:Metronidazole / Q000494:pharmacology; D013696:Temperature; D014107:Tosyllysine Chloromethyl Ketone / Q000494:pharmacology; D014246:Trichomonas vaginalis / Q000187:drug effects / Q000378:metabolism*
chemical_list: D008795:Metronidazole; D014107:Tosyllysine Chloromethyl Ketone; D008274:Magnesium; D002118:Calcium; D007460:Iodoacetamide