Histological alterations in gills and liver of rainbow trout (Oncorhynchus mykiss) after exposure to the antibiotic oxytetracycline

Publication date: July 2017 Source:Environmental Toxicology and Pharmacology, Volume 53 Author(s): S. Rodrigues, S.C. Antunes, B. Nunes, A.T. Correia The aim of this study was to investigate the histopathological effects of oxytetracycline (OTC) on the gill and liver tissues of rainbow trouts (Oncorhynchus mykiss) following acute (96h: 0.005–50mg/L) and chronic (28days: 0.3125–5μg/L) exposures. Results suggest the existence of a cause-and-effect relationship between the exposure to OTC and tissue damage. Most predominant disorders observed in gills were progressive (e.g. hypertrophy of mucous cells and hyperplasia of epithelial cells) in acute exposure and regressive (e.g. lamellar fusion, epithelial lifting of lamellae and some changes in tissue architecture) in chronic exposure. However, only the acute exposure was responsible for a significant increase of the total gill pathological index. PAGE index, reflecting the extent of gill tissue available for gas exchanges in fish, remained unchanged for both exposures. In liver, circulatory (e.g. hemorrhage and increase of sinusoidal space), regressive (e.g. pyknotic nucleus, vacuolization and hepatocellular degenerations) and progressive (e.g. hypertrophy of hepatocytes) changes were observed, but just after acute exposure. After chronic exposure, only inflammatory changes (e.g. leucocytes infiltration) were observed. Following both exposures, a significant increase of the total liver pathological index was recorded. ...
Source: Environmental Toxicology and Pharmacology - Category: Environmental Health Source Type: research