Serum transaminases activity and histopathological changes in Clarias lazera chronically exposed to nitrite

Increase in serum transaminases (GOT and GPT) activity attributable to nitrite toxicity was observed in juvenile Clarias lazera after chronic exposure to nitrite. The application of SGOT and SGPT assays for monitoring the effect of nitrite exposure over a 6-month period has shown that changes in activities are correlated with histological effects in Clarias liver. Kidneys from fish exposed to nitrite were not noticeably different histologically from that of control fish. Hypertrophy and hyperplasia were the most consistent lesions that occurred in the gills. Lifting of lamellar epithelium and necrosis of some epithelial cells were also prominent.