Effects of two weeks of food restriction on toxicological parameters in cynomolgus monkeys

Abstract

Animals frequently eat less after test-article treatment in non-clinical toxicological studies, and it can be difficult to distinguish test article-derived toxicities from secondary changes related to this reduced food intake. Therefore, in this study, we restricted the food intake of cynomolgus monkeys (Cambodian, male, n=2 or 3, 4-year ± 3month-old) to 25% of control for two weeks, and evaluated its effect on toxicological parameters (general conditions, body weight, electrocardiography, urinalysis, hematology, blood chemistry, bone marrow analysis, pathological examination). After 2 weeks, these monkeys exhibited decreases in bone marrow erythropoiesis (e.g. decreases in reticulocytes and bone marrow erythrocytes), glycogenesis induction (e.g. increase in AST), and malnutrition (e.g. decrease in triglyceride and systemic adipocytes atrophy). Additionally, histopathological analysis revealed granuloma and inflammatory cell infiltration in coronary fat, which had never been found in previous food restriction studies using other animal species. These findings will enable researchers to more accurately evaluate the toxicological risks of test-articles that simultaneously induce food intake reduction.