ABSTRACT
Carcinogenic test is an important part of non-clinical safety evaluation of new drugs, which aims to evaluate and predict the human carcinogenic risk in long-term drug use by examining the potential carcinogenic effects of drugs on animals. Historical control data may be vital in the interpretation of rare tumors and unexpected increases or decreases of tumors in treated animals compared to controls. Foreign institutions have accumulated a considerable amount of historical control data that can be attributed to the pathological working group and peer review. Such data is valuable and referable, and can be used as a reliable comparator for concurrent study-specific control data. Different experimental animal strains have evolved in history from the F344 rat and B6C3F1 mice, which were traditionally employed by the National Toxicology Program (NTP), to the SD rats, CD-1 mice, and Wistar rats that were routinely used by industrial firms, and finally to the strains of the p53+/- and Tg.rasH2 transgenic mice. It is true that each strain of rodent animal used in carcinogenicity test has different characters in tumorigenesis. Carcinogenicity tests are increasing in China, but the background data that can be referred to is limited so that how to accumulate and use our own historical control data has become challenging. This article summarizes and compares the tumor lesion data of the collected rodent animals, and concludes that different strains have specific types of tumors with gender-related difference.
ABSTRACT
Reference ranges of standard experimental parameters are useful for comparisons in toxicology. The aim of this study was to collect data from 13-week repeated toxicity studies in Crl:CD (SD) rats, a strain widely used for toxicity and efficacy research, for establishing domestic reference values. Data on body weight, food consumption; urinalysis, hematological, and blood biochemical parameters; and organ weights were collected from 11 toxicity studies in 220 Crl:CD (SD) rats (110 males and 110 females). The studies had been performed at a single testing facility over the last 5 years and involved animals sourced from a single breeder. The findings were collated as means, standard deviations, percentages, and ranges. Urine volume, uterus weight, eosinophil, and basophil counts, and triglyceride, total bilirubin, and gamma-glutamyl transpeptidase levels showed standard deviations of 30% or more. These historical control data would help to interpret the effects of test substances in routine toxicity and efficacy studies.