Mortality, body weight, food and water consumption, and clinical signs in Slc: B6C3F1 (C57BL/6 x C3H) mice utilized in chronic toxicity and carcinogenicity studies.

In vivo historical control data for Slc: B6C3F1 mice, including mortality, body weight, food and water consumption, and clinical signs and which were obtained from long-term toxicity and carcinogenicity studies (11 male and 12 female studies) conducted at the Biosafety Research Center, Foods, Drugs and Pesticides, (An-Pyo Center) during the last five years are presented. Mean survival at 83 and 109 weeks of age was 96.4% (min: 94.0%, max: 100%) and 79.0% (min: 74.0%, max: 86.0%) in males and 98.7% (min: 96.0%, max: 100%) and 81.7% (min: 70.0%, max: 90.0%) in females, respectively. The maximum mean body weight of males and females was 45.1 +/- 3.1 g (mean +/- S.D.) and 39.2 +/- 4.1 g, respectively. Male mice attained their maximum body weight at 72.7 +/- 4.3 weeks of age and females at 76.2 +/- 5.9 weeks of age. Clinical symptoms increased with age, particularly after week 84, and included: wasting, piloerection and palpable abdominal masses. Hypothermia and auricular pallor were common findings in moribund animals from week 79 to 104 of the studies. The use of in-house, historical control data can prove invaluable in the evaluation and interpretation of experimental results, especially in long-term and life-time studies.

Mortality, body weight, food and water consumption, and clinical signs in F344/DuCrj rats in studies of chronic toxicity and carcinogenicity.

In vivo historical control data, including mortality, body weight, food and water consumption, and clinical signs in F344/DuCrj rats were obtained from 11 long-term toxicity and carcinogenicity studies conducted at the Biosafety Research Center, Foods, Drugs and Pesticides, (An-Pyo Center) during the last five years. Survival at 109 weeks of age was 80.2% (min: 74%, max: 90%) in males and 80.5% (min: 72%, max: 92%) in females. The maximum mean body weights of males and females were 443.3 +/- 15.8 g (mean +/- S. D.) and 295.7 +/- 13.3 g respectively. Male rats attained their maximum body weight at 82.6 +/- 5.3 weeks of age, the females at 103.5 +/- 2.5 weeks of age. Clinical symptoms increased with age, particularly after 84 weeks of age, and included: wasting, piloerection, palpable subcutaneous and abdominal masses, and decreased spontaneous movement. Lowered body temperature and auricular pallor occurred commonly in moribund animals. The nature and grade of toxicity in the treated animals were generally disclosed by comparing with the behavior and signs in the control animals. The use of in-house, historical control data can be useful in subsequent evaluations of chronic toxicity and carcinogenicity studies.