The stress-protein response is a conserved and ubiquitous protective mechanism that enables cells to tolerate a wide variety of environmental insults. This response involves the decreased translation of “normal” genes and the increased translation of stress protein genes, resulting in the preferential synthesis of suites of proteins of different molecular weights. These proteins perform a variety of functions such as protein folding and renaturation, multimeric protein assembly, steroid receptor binding, and heme catabolism.
To evaluate the potential use of this protective response as a biomonitoring tool, we used a stepwise plan that proceeded through various in vivo laboratory chemical exposures. Brain, gill, and striated muscle tissues of fathead minnows (Pimephales promelas) exposed to arsenite, chromate, lindane, and diazinon were found to elicit the stress protein response (SPR) at environmentally realistic concentrations. Data accumulated from all experiments suggest that the SPR has potential as an indicator of both general stress and chemical specific exposure. Briefly, a 70-kD protein (sp70) was found to be induced by all four chemicals, whereas 20- and 30-kD proteins were indicative of metal exposure. Moreover, increased stress responses occurred in target tissues in relation to chemical mode of action. The potential utility of the SPR as a tool for assessing water quality is discussed.