zearalenone and Fish-Diseases

Zearalenone (ZEA) is a mycoestrogen frequently found in food and animal feed materials all over the world. Despite its hydrophobic character, ZEA is also found in surface and ground waters which suggests an environmental risk for aquatic animals. Knowledge concerning mycotoxin-related mechanisms of toxicity is still incomplete, e.g. little is known about the influence of ZEA exposure on fish. The aim of this study was to investigate the effect of ZEA on selected biochemical parameters in juvenile rainbow trout after 24, 72, and 168 h of intraperitoneal exposure (10 mg/kg of body weight). The analysis showed a slight tendency towards prolonged blood clotting time and significant iron deficiency in the liver and ovary of exposed animals. However, no differences in aminotransferase (AlaAT, AspAT) activity or glucose levels in fish plasma was observed. The results of this study suggest that although trout exposed to ZEA did not exhibit any distinct symptoms of liver damage, the mycotoxin tested was able interfere with blood coagulation and iron-storage processes.

Topics: Animal Feed; Animals; Blood Coagulation; Diet; Female; Fish Diseases; Food Contamination; Iron; Liver; Oncorhynchus mykiss; Ovary; Zearalenone

The mycotoxin zearalenone (ZEN) is a frequent contaminant of animal feeds, but its effects on fish have not yet been investigated extensively. In order to fill this gap a feeding trial with juvenile carp was conducted. Three groups of fish were fed feeds contaminated with ZEN at three concentrations (low: 332 μg kg(-1), medium: 621 μg kg(-1), and high: 797 μg kg(-1) feed) for four weeks. Possible reversible effects of ZEN were evaluated by feeding additional groups with the ZEN-contaminated feeds for four weeks, followed by the uncontaminated diet for two weeks. Immune function of isolated leukocytes from head kidney and trunk kidney was assessed using the assessment of NO production, the respiratory burst assay, the chemiluminescence assay, and the measurement of arginase activities. These investigations frequently revealed increased immune responses after exposure of fish to low ZEN concentrations and reduced immune responses after exposure to high mycotoxin concentrations. Moreover, the feeding of the uncontaminated diet for further two weeks did not improve the immune responses in most cases. These results indicate that cellular immune functions in ZEN-contaminated carp are influenced which may be relevant for fish health in aquaculture.

Topics: Animal Feed; Animals; Carps; Fish Diseases; Immunomodulation; Kidney; Leukocytes; Nitric Oxide; Zearalenone