© 1991 Oxford University Press
research-article |
Target Organ Toxicity and Leukopenia in Fischer 344 Rats Given Intravenous Doses of Vinblastine and Desacetyl Vinblastine
Toxicology Division. Lilly Research Laboratories, A Division of Eli Lilly and Company Greenfield, Indiana 46140
Received November 26, 1990; accepted May 2, 1991
Target Organ Toxicity and Leukopenia in Fischer 344 Rats Given Intravenous Doses of Vinblastine and Desacetyl Vinblastine. ZIMMERMANN, J. L., TODD, G. C., AND TAMURA, R. N. (1990). Fundam Appl Toxicol 17, 482–493. The toxicity and leukopenia produced by vinblastine or desacetyl vinblastine were established in 1-month studies in rats. Groups of male Fischer 344 rats were given weekly intravenous doses of vinblastine or desacetyl vinblastine at doses of 0.08, 0.16, 0.32, 0.64, or 1.28 mg/kg. The target organ toxicity was similar for both compounds. Decreased cell production in the thymus, testes, and bone marrow was produced in the animals of the two highest dose groups for both compounds with the degree of seventy greater in the highest dose group. All high dose rats (1.28 mg/kg) given desacetyl vinblastine and three rats given vinblastine died prior to study termination. Body weight loss was more pronounced in high dose rats given desacetyl vinblastine, but at lower doses there were no significant differences in body weight reduction for rats receiving either compound. Leukopenia occurred at all dose levels of 0.32 mg/kg and higher. During the first 2 weeks of the study, rats given 1.28 mg/kg of desacetyl vinblastine had a greater leukopenic response than rats given 1.28 mg/kg of vinblastine. It is concluded that both compounds produced similar target organ toxicity and leukopenia without deaths at doses of 0.32 and 0.64 mg/kg given once a week for 4 weeks. At the high dose (1.28 mg/kg) desacetyl vinblastine was more toxic than vinblastine resulting in greater mortality and body weight reduction.