The vibrating probe as a sensitive toxicological assay for the effects of tributyltin on ionic currents in Acetabularia mediterranea

Attempts to determine threshold response effects of toxic substances in cellular systems are often hampered by assays whose lower limit of detection is inadequate or by the use of invasive procedures that can produce artefacts. The non-invasiveness and sensitivity of the vibrating probe make this technique an ideal candidate to explore as a toxicological assay. The vibrating probe was used to study the effect of tributyltin (TBT) on extracellular currents from the large-celled marine algae A cetabularia mediterranea. TBT is used as an anti-fouling agent in marine paints, and it appears in seawater samples from many harbours. It is highly toxic to a variety of species including humans. Effects on membrane currents were found on exposure to levels of TBT as low as 2 ppb (6n m). This is approximately an order of magnitude lower than previously reported cellular effects from short-term TBT exposure and within the range of environmental TBT levels.