摘要：Data from the National Cancer Institute/National Toxicology Program (NCI/NTP) carcinogenesis bioassays were examined to compare cancer risks in rats and mice. Only those bioassays where chemicals were administered orally were used. The ratios for rats to mice of the virtually safe dose (VSD) levels associated with a risk of 10(-6) were compared. Comparisons of the ratios were made for those chemicals that NCI/NTP determined to be carcinogenic in at least one species and that showed a dose response trend in the same sex at the same tissue/organ site in the other species. In all, 69 comparisons from 38 carcinogens were performed. The overall geometric mean of the VSD ratios is 1.27 in terms of concentration (ppm); the mean and the standard deviation in logarithm are 0.24 and 1.83, respectively. The VSD ratios vary from 1:51 to 49:1. Without the restriction of the same sex and site, the geometric mean of the minimum VSDs is 1.38, and the standard deviation in logarithm is 1.79. By directly comparing the VSDs for rats and mice (as they are performed for risk assessment), this study showed a probability of 0.10 that the ratio of VSDs is greater than 10, and the ratio is greater than 20 with a probability of 0.05 when a chemical is carcinogenic in both species. Full text Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (850K), or click on a page image below to browse page by page. Links to PubMed are also available for Selected References . 305 306 307 308 309
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