Effect of Sodium Dodecyl Sulfate on RVD of digestive cells of Mytilus galloprovincialis

Aquatic pollutants produce multiple consequences at organism, population, community and ecosystem level, affecting organ function, reproductive status, population size, species survival and thus biodiversity. Among these, detergents are a big concern reaching aquatic ecosystems by different sources. Anionic detergents such as Sodium Dodecyl Sulfate (SDS), produce their toxic effects on aquatic organism primarily by their ability to absorb onto and penetrate cell membrane. In this work the effect of SDS at cellular level was tested by studying the effect of the detergent on RVD (regulatory volume decrease) on digestive cells of digestive gland of Mytilus galloprovincialis. For this purpose the mussels were exposed to two different concentration of SDS (0.1 mg/l and 1mg/l) for 10 and 18 days. The ability to perform RVD was evaluated by videometric technique in isolated cells from control and detergent exposed animal, exposed to hypotonic shock. The viability of cells was tested by Trypan blue test at the end of each experiments. We found that the cells of the exposed animals, unlike those of the control ones, were not able to perform RVD. The impairment of the homeostatic response was observed in all the experimental conditions above mentioned. However on the application of the hypotonic stress the initial swelling exhibited a dependence on the detergent exposition time at both the concentrations tested. Moreover, the lysosomal stability (by neutral red retention method) was altered. Our results suggest that the RVD could be useful to assess the adverse effect of sublethal concentrations of detergents at cellular level.