A new method for in vitro detection of microbially produced mitochondrial toxins

D Hoornstra, MA Andersson*, R Mikkola, MS Salkinoja-Salonen

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

Abstract

Sperm motility inhibition assay, earlier shown valuable for the detection of food poisoning non-protein toxins of Bacillus species was developed into an assay useful for specific detection of mitochondria damaging toxins. This was done by assessing the dissipation of the mitochondrial inner membrane transmembrane potential, Deltapsi(m) under conditions where the plasma membrane permeability barrier remained intact. The Deltapsi(m) was estimated as the intensity of orange JC-1 fluorescence in the mitochondrial sheath of the exposed spermatozoa. The plasma membrane integrity of the same cells was assessed by observing the exclusion of propidium iodide from the cytoplasm. Three types of mitochondrial toxic responses to microbially made bioactive substances were recognised. Mitochondrial toxicity by gramicidin (A., B, C, D), nigericin, salinomycin, narasin, monensin, calcimycin and antimycin A was characterised by gradual fading of the JC-1 fluorescence in the mitochondria. Dissipation of the Deltapsi(m) by cereulide, valinomycin and enniatin (A, A(1), B, B-1) was visible as spotwise quenching of the mitochondrial JC-1 fluorescence. In addition these substances caused hyperpolarisation of the plasma membrane. Oligomycin (A, B, C), ionomycin and staurosporine inhibited the spermatozoan motility, but Deltapsi(m) was fully preserved. Surfactin and lichenysin A caused mitochondrial damage at concentrations where the plasma membrane was also damaged. (C) 2003 Elsevier Ltd. All rights reserved.

Original languageEnglish
Pages (from-to)745-751
Number of pages7
JournalTOXICOLOGY IN VITRO
Volume17
Issue number5-6
DOIs
Publication statusPublished - 2003
MoE publication typeA1 Journal article-refereed
EventInternational Workshop on In Vitro Toxicology - Formia, Italy
Duration: 16 Oct 200119 Oct 2001
Conference number: 12

Keywords

  • JC-1
  • boar sperm
  • sperm motility
  • BACILLUS-CEREUS
  • EMETIC TOXIN
  • SPERM MOTILITY
  • CAPACITATION
  • APOPTOSIS
  • FERTILITY

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