Development of renal toxicity in F344 rats gavaged with mercuric chloride for 2 weeks, or 2, 4, 6, 15, and 24 months.

Both sexes of F344 rats were gavaged with maximal tolerated doses of mercuric chloride for periods from 2 wk to up to 2 yr to investigate chronic nephrotoxicity and potential carcinogenicity. The toxicity of mercuric chloride was excessive after 2 wk of exposure to doses ranging from 1.25 to 20 mg/kg, compromising renal function by selectively destroying cells of the proximal tubules, and eliciting marked elevations in urinary biomarker enzymes diagnostic for acute renal tubule necrosis.

Nonneoplastic nasal lesions in rats and mice.

Rodents are commonly used for inhalation toxicology studies, but until recently the nasal passages have often been overlooked or only superficially examined. The rodent nose is a complex organ in which toxicant-induced lesions may vary, depending on the test compound. A working knowledge of rodent nasal anatomy and histology is essential for the proper evaluation of these responses.

Normal histology of the nasal cavity and application of special techniques.

There are three major epithelial types in the nasal mucosa, in addition to numerous accessory structures, some of which are species specific. Without careful and consistent processing of the nose tissue, histopathologic assessment of lesions in the nasal cavity may be compromised. While formalin fixation may be used for routine review of the nasal cavity, Bouin's fixation provides better histologic detail and fewer artifacts.

Acute toxicity of perfluorodecanoic acid in C57BL/6 mice differs from 2,3,7,8-tetrachlorodibenzo-p-dioxin.

Perfluorodecanoic acid (PFDA) is a 10-carbon straight-chain fatty acid. Its toxicity in rats has been reported to resemble that produced by exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Mice which are "responsive" to TCDD toxicity carry the Ahb allele, while mice homozygous for the Ahd gene are less sensitive to TCDD toxicity.