Physiological parameters in ecotoxicology.

1. Regulated physiological parameters are normally maintained at a constant level by regulatory mechanisms. Acute toxic effects develop whenever a pollutant causes a regulated parameter to be displaced beyond tolerated limits, and thus, regulated parameters may be convenient toxicity parameters. The present study indicates that delta mu Na+ across the adductor muscle membrane of Mytilus edulis is a regulated parameter, and that injuries develop whenever this parameter drops below -700 J/mole. 2. Regulatory physiological parameters may display quick and substantial changes when regulatory mechanisms are activated to counteract variations in the regulated parameters. Thus, regulatory parameters may be used as sensitive alarm parameters in environmental monitoring. The present results indicate that the phosphate index [(ATP x P-arginine)/(Pi)2], metabolic rate and strombine may be used as alarm parameters. 3. The combined response of all parameters may provide a pollutant-specific fingerprint in environmental monitoring.