Evoked potential changes from 13 weeks of simulated toluene abuse in rats.

Fischer 344 rats were exposed to 8000 ppm toluene vapor in an 'abuse' paradigm for 13 weeks to develop an animal model for 'solvent neurotoxicity.' Exposures to toluene were multiple and short (15 to 35 min), adjusted according to tolerance. Although body weight was reduced 23% from controls, the toluene-exposed rats appeared healthy.

Chronic toxicity and oncogenicity of picloram in Fischer 344 rats.

The chronic toxicity and oncogenicity of the herbicide picloram was studied in male and female Fischer 344 rats administered 0, 20, 60, or 200 mg/kg.d technical-grade picloram via their feed for 2 yr. A comprehensive set of in-life and clinical pathology parameters was measured and an extensive list of tissues was examined grossly and by light microscopy from control and treatment groups of animals.

Similarities of toluene and o-cresol neuroexcitation in rats.

Exposure to high concentrations of toluene vapors, or to intravenous o-cresol (a toluene metabolite) at about 0.9 mg/min, caused excitation of the somatosensory evoked potential (SEP) and EEG of Fischer 344 rats. SEP excitation was characterized by a large increase in a positive waveform at about 20-50 msec.

Acute, pharmacokinetic, and subchronic toxicological studies of 2,4-dichlorophenoxyacetic acid.

The single-dose oral LD50 values in Fischer 344 rats for technical-grade, 2,4-dichlorophenoxyacetic acid (2,4-D), esters, and salts ranged from 553 mg/kg (isobutyl ester in females) to 1090 mg/kg (dimethylamine salt in males). The LD50 values for the acid, esters, or salts, when expressed as acid equivalents, were consistent which suggests that the acute toxicity was due to 2,4-D per se. Acute dermal LD50 values in rabbits for the acid, esters, and salts were greater than 2000 mg/kg.

Dietary toxicity of picloram herbicide in rats.

The toxicity of orally administered technical-grade picloram was evaluated in male and female Fischer 344 rats. Dietary dose levels were up to 2000 mg/kg body weight (bw) X d for 2 wk, 500 mg/kg bw X d for 13 wk, or 200 mg/kg bw X d for 12 mo. Routine indices of toxicity were evaluated at all of the respective time periods.