Abstract
Organotin compounds have been used as anti-fouling reagents having high toxicity to aquatic organisms. In this study, in order to assess the toxic effects of triphenyltin on fish, potential activities of chymotrypsinogen and trypsinogen in the liver of red sea bream, Pagrus major, and the activities of chymotrypsin and trypsin in the intestine were determined. The red sea bream were exposed to triphenyltin ranging from 0.13μg/l to 3.23μg/l for up to 8 weeks. The potential activities of chymotrypsinogen and trypsinogen in the liver of exposed fish were much lower than those in the control fish, whereas the active forms of these enzymes in the intestine were not affected by the exposure to triphenyltin. The feeding activity of fish exposed to tiphenyltin of 3.23μg/l was depressed. The results of the relationship between diet amounts given and enzyme activities suggested that starvation caused a remarkable decrease in the potential activities of the zymogens in the liver, suggesting the depression of potential activities of the zymogens in the liver of exposed fish was not caused by the change in feeding activity of fish but by the toxic effects of triphenyltin. The potential activities of the zymogens were influenced by the exposure to triphenyltin of 0.13μg/l for 4 weeks.
