Effects of 5-vinyloxazolidine-2-thione on lactating rats and their sucklings.

5-vinyloxazolidine-2-thione (VOT) administered orally to lactating rats was found to be efficiently transferred to the sucklings via the milk. In mothers the exposure to VOT resulted in an increased percentage of neutrophils, a decreased percentage of lymphocytes and increases in the relative weights of liver and thyroid. Suckling rats showed a decreased number of leucocytes, increases in the relative weights of liver and thyroid and structural changes in the thyroid. Male sucklings were more affected than female pups. The antithyroid effects were clearly related to the maternally administered VOT doses.

[The subchronic toxicity of 5-vinyloxazolidine-2-thione in rats]. / Untersuchung der subchronischen Toxizität von 5-Vinyloxazolidin-2-thion an Ratten.

Groups of male and female rats received 5-vinyloxazolidine-2-thione (VOT) in their drinking water for 13 weeks at concentrations of 0, 10, 25, 50 or 100 mg/l and 0, 2.5 or 5 mg/l respectively. Compared with the controls, there were decreases in food intake and growth of females given VOT-doses of 10 mg/l and higher. Liquid intake was reduced in males and females of the highest dose group. Terminal haematological examination revealed an increase in white cell count at the 50 and 100 mg levels in females and a reduction in the red cell count at 100 mg/l in males. Organ weight changes were dose-related increases in the relative thyroid and liver weight and a decrease in the relative thymus weight. Structural and functional changes of the thyroid were observed in animals at levels of 10 mg/l and higher. Histological examinations of the kidneys showed tubulonephrosis in animals at and above a VOT-level of 5 mg/l. The no-observed-effect level (NOEL) established from these studies was 2.5 ml VOT/l drinking water (approximately equivalent to an daily intake of 0.4 mg/kg body weight).

[Significance of gastrointestinal microflora for the metabolism of foreign compounds]. / Die Bedeutung der Gastrointestinalflora für den Fremdstoffmetabolismus.

Microbiological biotransformation as a part of metabolism of foreign compounds in general, has great toxicological consequences. An overview on the most important types of reactions is given. In detail, comparative investigations of the metabolism of gamma-HCH, azobenzene and progoitrin in germfree and conventionalized rats are described and results from the literature are presented.

The metabolism of some xenobiotics in germ-free and conventional rats.

The different participation of the gastrointestinal microflora in the biotransformation of gamma-hexachlorcyclohexane (gamma-HCH), azobenzene and the isolated glucosinolate progoitrin was studied. Marked dehydrochlorination of gamma-HCH to gamma-pentachlorcyclohexene (PCCH) also occurs without participation of the microflora. Azobenzene was reduced in germ-free (g) and conventional (c) rats to hydrazobenzene but was split to aniline only in c-rats. Progoitrin was split with and without the influence of the microflora, but the splitting was more complete in rats with intact gastrointestinal flora.

[Determination of residues of the fungicide benzimidazole carbamic acid methyl ester and its metabolites 2-aminobenzimidazole and benzimidazole]. / Zur Rückstandsbestimmung des Fungizides Benzimidazolcarbamidsäuremethylester und seiner Metabolite 2-Aminobenzimidazol und Benzimidazol.

The authors describe a method for extracting and determining benzimidazole carbamic acid methyl ester (MBC) in the presence of its metabolites 2-aminobenzimidazole and benzimidazole. The determination is performed thin-layer and paper chromatographically using visual spot comparison. A sensitive biological method is employed for the detection of MBC. The metabolites are assayed by chemical procedures. The smallest amounts of residues that the authors could detect were: 0.01 p.p.m. of MBC and approximately 0.2 p.p.m. of the metabolites, the recovery rate ranging from 70--85%.