Regulatory toxicology and pharmacology : RTP
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Regul. Toxicol. Pharmacol. · Jun 2004
Allometric principles for interspecies extrapolation in toxicological risk assessment--empirical investigations.
Four types of data (toxicokinetic data of pharmaceuticals from six species including humans, LD(50) values from eight animal species, long-term NOAEL values of pesticides from mice, rats, and dogs, and toxicity data on anti-neoplastic agents from six species including humans) were used for interspecies comparisons. Species differences with regard to kinetic parameters and toxicity were evaluated and the concordance with predictions by allometric scaling according to caloric demand (allometric exponent 0.75) or to body weight (allometric exponent 1) was checked. For LD(50) values, agreement was poor for both allometric concepts. ⋯ The other three datasets are clearly in agreement with the allometric scaling according to caloric demand. Caloric demand scaling is thus proposed as a generic interspecies extrapolation method in the absence of substance-specific data. Moreover, the evaluated data make it possible to describe uncertainty associated with the process of interspecies extrapolation by allometric rules.
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Regul. Toxicol. Pharmacol. · Jun 2004
Embryotoxicity and teratogenicity study with alpha-cyclodextrin in rats.
The embryotoxicity/teratogenicity of alpha-cyclodextrin (alpha-CD) was examined in Wistar Crl:(WI)WU BR rats. alpha-CD was fed at dietary concentrations of 0, 1.5, 5, 10, or 20% to groups of 25 pregnant female rats from day 0 to 21 of gestation. An additional group received a diet with 20% lactose. The additions to the diet of alpha-CD and lactose were made at the expense of pregelatinized potato starch. ⋯ Maternal reproductive performance was not affected by the alpha-CD treatment. Examination of the fetuses for external, visceral and skeletal changes did not reveal any fetotoxic, embryotoxic, or teratogenic effects of alpha-CD. In conclusion, no adverse effects were observed at alpha-CD intakes of up to 20% of the diet, the highest dose level tested at which the rats consumed about 13 g/kg bw/day.