Food and cosmetics toxicology最新文献

Cyclohexylamine (CHA), the principal metabolite of cyclamate, was given by oral gavage to male rats (200 mg/kg/day) and male Beagles (250 mg/kg/day) for 9 wk. Subsequently some of these animals were maintained undosed for 13 wk to assess recovery. CHA adversely affected body-weight gain and food consumption in both species. Although a degree of tolerance developed, vomiting tended to occur after CHA administration to dogs. Serum follicle stimulating hormone levels increased and testosterone levels decreased in rats given CHA. No effects were found on the serum luteinizing hormone and testosterone levels in dogs, but reversible effects on sperm morphology were induced in this species. There were no statistically significant (P > 0·05) effects on the weight of the pituitaries, testes or secondary sex organs of either species. The only lesion detectable by conventional histological examination was focal atrophy of seminiferous tubules in one rat examined 13 wk after cessation of CHA treatment. Quantitative assessment of testicular spermatogenesis showed that CHA administration reduced the counts of pachytene spermatocytes, and of early and late spermatids, in both species. These effects were apparently reversible in dogs but not in rats.

Biotransformation studies with phenylurea and the three isomers of monochlorophenylurea were performed using an isolated perfused rat-liver preparation. In the perfusate and the bile, ring-hydroxylation was detected only with phenylurea and with o- and m-chlorophenylurea, and yielded the corresponding p-hydroxylated compounds in each case, while with p-chlorophenylurea no ring hydroxylation was observed at the ortho or meta position. Similar results were obtained with the arylhydroxylation of the herbicide monolinuron (3-(4-chlorophenyl)-1-methoxy-1-methylurea) in the perfused rat liver. In contrast, studies of monolinuron biotransformation in vivo in rats, pigs and hens showed that ring hydroxylation at the ortho or meta position was the main degradation step. The possible reasons for the difference in biotransformation in vivo and in vitro are discussed.

Male, weanling Sprague-Dawley rats were fed a diet containing 206 μg tin (as stannous chloride)/g feed for 21 days. The rats fed the test diet lost significantly more zinc in their faeces and retained significantly lower levels of zinc in their tibias and kidneys than rats fed the control diet (which contained 1 μg tin/g). The rats fed the tin-supplemented diet retained significantly higher levels of tin in their kidneys and tibias and significantly lower levels of copper in their kidneys than the control animals.

The size spectra of respirable particulates from five cosmetic aerosol products were determined using the methods of microscopy, cascade impaction, and single particle aerodynamic relaxationtime (SPART) analysis. In order to facilitate methodological comparisons, the same sampling apparatus was used in all phases of the study. The results obtained using the three methods were similar in most cases. The pressurized aerosol products produced particulates with count median diameters of 0·6-1·5 μm and mass median diameters of 2·2–3·2 μm as measured by all methods. The pump spray also yielded particulates with median diameters in these ranges in the microscope and SPART analyses, but in the cascade impaction analysis, the mass median diameter was determined to be 12·8 μm.

Groups of 57 Wistar rats of each sex were maintained on diet containing 0.25 or 1% butylated hydroxytoluene (BHT) for 104 wk; control groups comprised 36 rats of each sex. Treated rats of both sexes showed reduced body-weight gain, relative spleen weight and white-blood-cell count while in the males there was also a reduction in serum triglyceride. BHT-treated animals of both sexes showed increased relative liver weight and total blood cholesterol but increases in red-blood-cell count could be seen only in females and only the males showed increased γ-glutamyltransferase. No significant histological changes were observed in the liver or haematopoietic system to explain these haematological and biochemical changes. Tumours were found in the liver, pancreas, mammary glands, uterus, pituitary gland, adrenal glands and in some other organs of some of the treated rats, but their incidence was not significantly different from that in controls. This experiment showed no carcinogenic effect of BHT on rats.