Abstract
The chance that alternatives will completely replace animals for toxicology research in the foreseeable future is nil. Continual refinement of animal toxicity and carcinogenesis studies, however, can be an effective means of reducing the numbers of animals used and conserving time and resources without compromising scientific quality. We must continue to strive to find species and strains that can metabolize chemicals similar to humans, are small enough to be housed in large numbers, and have low prevalence of spontaneous lesions with sufficient life span to express the toxic and carcinogenic potential of chemicals. Adequate care of animals with control of variables such as light, temperature, diet, bedding, diseases, and genetic characters of laboratory animals will decrease the variability. Humane considerations and euthanasia of animals with large masses and other conditions interfering with eating and drinking, major injuries and ulcers related to husbandry and treatment, and diseases indicating pain and suffering will help not only to alleviate further pain and distress but also to facilitate collection of tissues without secondary complications for detection of chemical treatment-related lesions. Limiting the duration of studies to decrease the variability due to ageassociated changes will also refine long-term studies. Other considerations for refinement of carcinogenesis studies include selection of the most sensitive sex of one or more species for evaluation of selected chemicals in a class where toxic and carcinogenic potential of other representative chemicals are known. Genetically engineered animal models with known oncogenes may reduce the duration and increase the sensitivity of carcinogenesis studies with a reduction in the use of animals.
Footnotes
Presented at the 28th Annual Meeting of the Society of Toxicology, Atlanta, GA, February 26–March 3, 1989.
References
- Bellhorn R.W. Lighting in the animal environment. Lab. Anim. Sci. 1980;30:440–450. [PubMed] [Google Scholar]
- Boorman G.A., Hickman R.L., Davis G.W., Rhode L.S., White N.W., Griffin T.A., Mayo J., Hamm T.E., Jr. Serological titers to murine viruses in 90-day and 2-year studies. In: Hamm T.E. Jr., editor. Complications of Viral and Mycoplasmal Infections in Rodents to Toxicology Research and Testing. Hemisphere; New York: 1986. pp. 11–23. [Google Scholar]
- Collins M.J., Jr. Prevalence of pathogenic murine viruses and mycoplasma that are currently a problem to research. In: Hamm T.E. Jr., editor. Complications of Viral and Mycoplasmal Infections in Rodents to Toxicology Research and Testing. Hemisphere; New York: 1986. pp. 1–9. [Google Scholar]
- Frederick G.L. The necessary minimal duration of final long-term toxicologic tests of drugs. Fundam. Appl. Toxicol. 1986;6:385–394. doi: 10.1016/0272-0590(86)90213-7. [Letters to the Editor on this subject (1987). 8, 134–138] [DOI] [PubMed] [Google Scholar]
- Goldberg A.M. Mary Ann Liebert, Inc; New York: 1985. (Alternative Methods in Toxicology Research, Vol. 3, In Vitro Toxicology: Progress Report from the Johns Hopkins Center for Alternatives to Animal Testing). [Google Scholar]
- Greenman D.L., Bryant P., Kodell R.L., Sheldon W. Influence of cage shelf level on retinal atrophy in mice. Lab. Anim. Sci. 1982;32:353–356. [PubMed] [Google Scholar]
- Greenman D.L., Kodell R.L., Sheldon W.G. Association between cage shelf level and spontaneous and induced neoplasms in mice. J. Natl. Cancer Inst. 1984;73:107–113. [PubMed] [Google Scholar]
- Grice H.C. Current Issues in Toxicology. Springer-Verlag; New York: 1984. Age associated (geriatric) pathology: Its impact on long-term toxicity studies; pp. 71–86. [Google Scholar]
- Haseman J.K., Huff J.E., Rao G.N., Eustis S.L. Sources of variability in rodent carcinogenicity studies. Fundam. Appl. Toxicol. 1989;12:793–804. doi: 10.1093/toxsci/12.4.793. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Haseman J.K., Huff J.E., Rao G.N., Arnold J.E., Boorman G.A., McConnell E.E. Neoplasms observed in untreated and corn oil gavage control groups of F344N rats and B6C3F1 mice. J. Natl. Cancer Inst. 1985;75:975–984. doi: 10.1093/jnci/75.5.975. [DOI] [PubMed] [Google Scholar]
- Haseman J.K., Huff J.E. Species correlation in long-term carcinogenicity studies. Cancer Letters. 1987;37:125–132. doi: 10.1016/0304-3835(87)90154-6. [DOI] [PubMed] [Google Scholar]
- Homburger F., Adams R.A., Bernfeld P., Van Dongen C.G., Soto E. A new firstgeneration hybrid Syrian hamster, BIO F1D Alexander for in vivo carcinogenesis bioassay, as a third species or to replace the mouse. Surv. Synth. Pathol. Res. 1983;1:125–133. [Google Scholar]
- Huff J.E., Melnick R.L., Solleveld H.A., Haseman J.K., Powers M., Miller R.A. Multiple organ carcinogenicity of 1,3-butadiene in B6C3F1 mice after 60 weeks of inhalation exposure. Science. 1985;227:548–549. doi: 10.1126/science.3966163. [DOI] [PubMed] [Google Scholar]
- Mehlman M.A. Princeton Scientific; Princeton, NJ: 1989. (Benchmarks: Alternative Methods in Toxicology). [Google Scholar]
- National Research Council . National Academy Press; Washington DC: 1988. (Report of the Committee on the Use of Laboratory Animals in Biomedical and Behavioral Research). [Google Scholar]
- National Toxicology Program, Board of Scientific Counselors . U.S. Department of Health and Human Services. Public Health Service; 1984. pp. 171–176. (Report of the NTP Ad Hoc Panel. on Chemical Carcinogenesis Testing and Evaluation). [Google Scholar]
- National Toxicology Program Toxicology and Carcinogenesis Studies of Nalidixic Acid. 1989 NTP Technical Report No. 368. [PubMed] [Google Scholar]
- Newberne P.M., Glasser O., Friedman J., Stillings B. Safety evaluation of fish protein concentrate over five generations of rats. Toxicol. Appl. Pharmacol. 1973;24:133–141. doi: 10.1016/0041-008x(73)90188-9. [DOI] [PubMed] [Google Scholar]
- Newcomer C.E., Fitts D.A., Goldman B.D., Murphy M.R., Rao G.N., Shklar G., Schwartz J.J. Experimental biology: Other research uses of Syrian hamster. In: Van Hoosier G.L. Jr., McPherson C.W., editors. Laboratory Hamsters. Academic Press; New York: 1987. pp. 285–287. [Google Scholar]
- Portier C., Hoel D. Optimal design of chronic animal bioassay. J. Toxicol. Environ. Health. 1983;12:1–19. doi: 10.1080/15287398309530403. [DOI] [PubMed] [Google Scholar]
- Rao G.N. Significance of environmental factors on the test system. In: Hoover B.K., Baldwin J.K., Ulner A.F., Whitmire C.E., Davies C.L., Bristol D.W., editors. Managing Conduct and Data Quality of Toxicology Studies. Princeton Scientific; Princeton, NJ: 1986. pp. 173–186. [Google Scholar]
- Rao G.N. Rodent diets for carcinogenesis studies. J. Nutr. 1988;118:929–931. doi: 10.1093/jn/118.8.929. [DOI] [PubMed] [Google Scholar]
- Rao G.N., Birnbaum L.S., Collins J.J., Tennant R.W., Skow L.C. Vol. 10. 1988. Mouse strains for chemical carcinogenicity studies: Overview of a workshop; pp. 385–394. (Fundam. Appl. Toxicol.). [DOI] [PubMed] [Google Scholar]
- Rao G.N., Piegorsch W.W., Crawford D.D., Edmondson J., Haseman J.K. Influence of viral infections on body weight, survival, and tumor prevalences of B6C3F1 (C57BL6N × C3HHeN) mice in carcinogenicity studies. Fundam. Appl. Toxicol. 1989;13:156–164. doi: 10.1016/0272-0590(89)90315-1. [DOI] [PubMed] [Google Scholar]
- Rao G.N., Haseman J.K., Edmondson J. Influence of viral infections on body weight, survival, and tumor prevalence in Fischer 344 rats of long-term studies. Lab. Anim. Sci. 1989;39:389–393. [PubMed] [Google Scholar]
- Tennant R.W., Morgolin B.H., Shelby M.D., Zeiger E., Haseman J.K., Spalding J., Caspary W., Resnick M., Stasiewicz S., Anderson B., Minor R. Prediction of chemical carcinogenicity in rodents from in vitro genetic toxicity assays. Science. 1987;236:933–941. doi: 10.1126/science.3554512. [DOI] [PubMed] [Google Scholar]
- Wiskemann A., Sturm E., Klehr N.W. Fluorescent lighting enhances chemically induced papilloma formation and increases susceptibility to tumor challenge in mice. J. Cancer Res. Clin. Oncol. 1986;112:141–143. doi: 10.1007/BF00404397. [DOI] [PubMed] [Google Scholar]