Evaluation of tributyltin toxicity in Chinese rare minnow larvae by abnormal behavior, energy metabolism and endoplasmic reticulum stress.

Tributyltin (TBT) is a ubiquitous contaminant in aquatic environment, but the detailed mechanisms underlying the toxicity of TBT have not been fully understood. In this study, the effects of TBT on behavior, energy metabolism and endoplasmic reticulum (ER) stress were investigated by using Chinese rare minnow larvae. Fish larvae were exposed at sublethal concentrations of TBT (100, 400 and 800 ng/L) for 7 days. Compared with the control, energy metabolic parameters (RNA/DNA ratio, Na(+)-K(+)-ATPase) were significantly inhibited in fish exposed at highest concentration (800 ng/L), as well as abnormal behaviors observed. Moreover, we found that the PERK (PKR-like ER kinase)-eIF2α (eukaryotic translation initiation factor 2α) pathway, as the main branch was activated by TBT exposure in fish larvae. In short, TBT-induced physiological, biochemical and molecular responses in fish larvae were reflected in parameters measured in this study, which suggest that these biomarkers could be used as potential indicators for monitoring organotin compounds present in aquatic environment.