Perinatal hexachlorobenzene toxicity in the mink

Area of Science:

• Toxicology
• Environmental Health
• Animal Science

Background:

• Hexachlorobenzene (HCB) is a persistent organic pollutant with known adverse effects on wildlife.
• Perinatal exposure to HCB can significantly impact offspring survival and development.
• Understanding the sub-lethal effects of HCB in adult animals is crucial for ecological risk assessment.

Purpose of the Study:

• To investigate the effects of dietary hexachlorobenzene (HCB) exposure on adult female mink and their offspring.
• To assess the impact of HCB on hepatic enzyme activity, liver and body weights, and renal function in mink.
• To determine the primary site of HCB disposition in exposed mink.

Main Methods:

• Adult female mink were fed diets containing 0, 1, or 5 ppm HCB and bred.
• Offspring were maintained until 16-17 weeks of age, then assessed for body and liver weights.
• Hepatic enzyme activity (cytochrome P-450, ethoxyresorufin-O-deethylase), renal function in vitro, and tissue histology were evaluated.

Main Results:

• No significant effects of HCB on body or liver weights were observed in 16-17 week old mink.
• Significant induction of hepatic cytochrome P-450 (2.0-fold) and ethoxyresorufin-O-deethylase (1.5-fold) occurred in the 5 ppm HCB group.
• No observable hepatic damage or alterations in renal function or morphology were detected; fat was the primary HCB storage site.

Conclusions:

• Dietary HCB exposure in mink leads to induction of hepatic mixed-function oxidases without causing overt hepatotoxicity or affecting growth.
• These findings contrast with known severe effects of perinatal HCB exposure, suggesting differential toxicity pathways.
• HCB is primarily sequestered in adipose tissue, influencing its toxicokinetics and potential for long-term effects.