Flow cytometry, morphometry and histopathology as biomarkers of benzo[a]pyrene exposure in brown bullheads (ameiurus nebulosus)

Abstract

Brown bullheads were given a single intraperitoneal dose of 0, 5, 25 or 125 mg kg-1 benzo[a]pyrene (BaP), a carcinogenic polycyclic aromatic hydrocarbon, and evaluated over 18 months. Flow cytometric analyses of hepatocyte DNA content indicated an increase in DNA synthesis in BaP-exposed fish prior to day 14 post-exposure. Thereafter, all flow cytometric variables returned to initial levels. Histopathological evaluation of livers from fish sampled at 18 months revealed significant differences among treatments in the amount of hepatic macrophage ceroid pigmentation and basophilic staining intensity. No neoplasms or changes in blood cell DNA content were detected. Significant morphometric variations existed among fish, but differences between sexes overshadowed differences attributable to dose. Flow cytometry yielded no evidence of long-term DNA alterations from a single exposure to BaP; however, the differences detected by DNA analysis shortly after the toxic event suggest that flow cytometric cell cycle analysis may be useful for documenting continuing exposures.

Histopathology investigation on the Vardar chub (Squalius vardarensis) populations captured from the rivers impacted by mining activities

“…This is in accordance with previous studies, which reported that presence of toxicants in the environment was not always associated with fluctuations in HSI. For example, exposure to paper mill effluent (Oikari and Niitylä, 1985), benzo(a)pyrene (Grady et al, 1992) or chromium picolinate (Mehrim, 2012) have not shown any effect on fish HSI. Similarly, our results for GSI, as well as microscopic investigations of chub gonads indicated good reproductive health.…”

Diagnostic criteria for proliferative hepatic lesions in brown bullhead Ameiurus nebulosus

“…At 7 mo, findings included numerous clear cell and eosinophilic foci, bile duct proliferation and fibrosis, and a cholangioma. In a second study, brown bullhead were injected with a single intraperitoneal dose of 0, 5, 25, or 125 mg kg -1 benzo[a]pyrene and evaluated over 18 mo (Grady et al 1992); one focus of biliary hyperplasia and fibrosis in a bullhead exposed to 25 mg kg -1 and basophilic foci at all exposure levels were observed at Day 540. None of these lesions were observed in control fish.…”

<b>The use of biomarkers for assessing effects of pollutant stress on fish species from a tropical river in Southeastern Brazil

“…The HSI is one of indices most often associated with exposure to contaminants (Grady, Mclaughlin, Caldwell, Schmitt, & Stalling, 1992;Hismayasari, Marhendra, Rahayu, Saidin & Supriyadi, 2015). Likewise, the liver is a primary detoxification organ in fish (Hinton & Laurén, 1990;Liebel et al 2013) and an important target organ related to important metabolic mechanisms.…”