Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
2065247 | Toxicon | 2010 | 8 Pages |
This study was designed to estimate the toxic threshold of male and female fish to microcystins based on different biomarkers. Japanese medaka (Oryzias latipes) were fed dietary Microcystin-LR (0, 0.46, 0.85, 2.01 and 3.93 μg MC-LR/g dry diet for 8 weeks at 25 °C. The results revealed that dietary MC-LR inhibited growth at the end of 8 weeks. The survival of embryos and the RNA/DNA ratio of whole fish decreased significantly (P < 0.05) in fish fed 3.93 μg MC-LR/g dry diet. Heat shock protein (Hsp60) expression was induced in the liver of female and male fish fed diets containing ≥0.85 and 0.46 μg MC-LR/g diet, respectively. The activity of liver caspase 3/7 was significantly higher in female fish fed 3.93 μg MC-LR/g diet and in males fed 2.01 MC-LR μg/g dry diet than fish fed the control diet. The threshold for inhibition of liver protein phosphatase expression was lower in female (2.01 μg/g diet) than that in male fish (3.93 μg/g diet). Histopathological examination showed significant single-cell necrosis in female and male medaka fed diets containing 0.85 and 3.93 μg MC-LR/g diet, respectively. Based on different biomarkers, this study demonstrated that dietary MC-LR is toxic to Medaka and the effects are gender dependent.