Estimating the oral bioavailability of methylmercury to channel catfish (Ictalurus punctatus)

Journal Article · Sat Aug 01 04:00:00 EDT 1998 · Environmental Toxicology and Chemistry

DOI:https://doi.org/10.1002/etc.5620170812· OSTI ID:675398

McCloskey, J T ^[1]; Schultz, I R ^[2]; Newman, M C ^[3]

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1. Univ. of Georgia, Aiken, SC (United States). Savannah River Ecology Lab.
2. Pacific Northwest National Lab., Richland, WA (United States)
3. Coll. of William and Mary, Gloucester Point, VA (United States). Virginia Inst. of Marine Science

In classical pharmacology, oral bioavailability of a toxicant is defined as that fraction of an orally administered dose reaching the systemic circulation of the animal. The present study estimates the bioavailability of methylmercury in channel catfish (Ictalurus punctatus) by comparing concentrations in the blood through time after oral and intra-arterial (IA) administration. Catfish were cannulated in the dorsal aorta and gavaged a pelleted feed that has been spiked with methylmercury. Each catfish was gavaged an increasing amount of spiked feed. Following oral dosing, serial blood samples were removed for more than 1,500 h. One month after removal of the last blood sample, the same fish were injected IA with methylmercury and serial blood samples were removed for more than 3,000 h. The area under the curve of the blood concentration-time curve extrapolated to infinity (AUC{sub 0{r_arrow}x}) was calculated from fish dosed orally and IA using both noncompartmental (trapezoidal) and compartmental methods. Bioavailability was estimated as the ratio of the dose-corrected oral AUC{sub 0{r_arrow}x} to the IA AUC{sub 0{r_arrow}x}. Average bioavailability estimates from this approach were 33% using noncompartmental methods and were correlated with the amount of food gavaged to the fish. Bioavailability estimates using the present methods were much lower than estimates using more conventional methods suggesting that conventional methods may overestimate the true bioavailability of toxicants in fish.

• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: FC09-96SR18546
• OSTI ID: 675398
• Journal Information: Environmental Toxicology and Chemistry, Journal Name: Environmental Toxicology and Chemistry Journal Issue: 8 Vol. 17; ISSN 0730-7268; ISSN ETOCDK
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
56 BIOLOGY AND MEDICINE
APPLIED STUDIES
BIOLOGICAL ACCUMULATION
BIOLOGICAL AVAILABILITY
FISHES
METHYLMERCURY
WATER POLLUTION