Effect of CdCl2 on Regulatory Volume Decrease (RVD) in Mytilus galloprovincialis digestive cells.

This study investigated the role of cadmium, a widespread heavy metal in the aquatic environment, on cell volume regulation of digestive cells isolated from the digestive gland of Mytilus galloprovincialis. These cells when exposed to a rapid change (from 1100 to 800 mOsm/kg) of the bathing solution osmolality swelled but thereafter underwent a Regulatory Volume Decrease (RVD), tending to recover the original size. This homeostatic response is altered by cadmium, as suggested by experiments performed both on isolated cells pre-incubated with cadmium (10(-5)M) and on cells isolated from animals exposed to sub-lethal concentrations of the metal (40 μg/l for 21 days). It is suggested that cytoskeleton and Na(+)/K(+)ATPase are the possible targets of cadmium which impairment is responsible of the altered homeostatic response.