Historical control data from 13-week repeated toxicity studies in Crj:CD (SD) rats

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.

Particle Size Dependent Teratogenicity of Silver Nanoparticles in Mice

“…Insignificant decreased of absolute liver weights observed in the treatment groups were also considered evidence for proof and not treatment-related, as the changes did not show a dose-response relationship and were within the limits of normal biological variations [27]. Our results agree with those of previous studies [25,26].…”

Evaluation of toxicity to triclosan in rats following 28 days of exposure to aerosol inhalation

“…The hematological changes observed in the TCS-exposed groups, including a decreased RET ratio in male rats in the 0.40 mg/L group, a decreased LYM ratio and increased NEU ratio in female rats in the 0.40 mg/L group, and decreased MCHC levels in female rats in the 0.13 mg/L group, were of no toxicological significance because they were only slightly different, were only observed in one sex, and did not show a dose-response relationship. Moreover, these values were unaccompanied by correlated findings in other hematological parameters and were generally within the normal historical ranges for control rats (Petterino and Argentino-Storino, 2006;Han et al, 2010;Lee et al, 2012).…”

“…Moreover, they were within the limits of normal biological variation (Petterino and Argentino-Storino, 2006;Han et al, 2010;Lee et al, 2012) and were not accompanied by correlated histopathological changes. The significant increases in relative brain and lung weights observed in male rats in the 0.40 mg/L group were of uncertain toxicological significance because the increases are considered to be the result of a reduction in body weight, and because there are no corresponding pathology results that accompanied these differences in organ weight.…”

Integrated analysis of toxicity data of two pharmaceutical immunosuppressants and two environmental pollutants with immunomodulating properties to improve the understanding of side effects—A toxicopathologist׳s view

“…In large sample sizes, 'spontaneously' occurring outliers are expected. Collection of historical data including spontaneous incidences of outliers within laboratory specific data is routinely done in toxicology (examples: Hayakawa et al, 2013;Lee et al, 2012;Okamura et al, 2011). In addition, the incidence of outliers in clinical chemistry or hematology and unusual histopathologic findings in controls is surveyed in larger databases.…”