title: Effect of cage population density on plasma corticosterone and peripheral lymphocyte populations of laboratory mice.
abstract: The effect of different population densities of mice per cage on plasma corticosterone, peripheral lymphocytes and specific lymphocyte subpopulations was investigated. The animals were housed in groups of 2, 4 or 8 mice per cage and the blood samples were taken from each animal of these groups on days one, 7 and 14. A significant elevation (P less than 0.05) in plasma corticosterone concentration was observed in the group of 8 mice per cage on days one and 7 as compared with those of 2 or 4 mice per cage. The number of peripheral lymphocytes was significantly decreased in the groups of 2 (P less than 0.01) and 8 (P less than 0.05) mice per cage as compared with the group of 4 mice per cage on day one. A significantly decreased number of lymphocytes (P less than 0.01) in the group of 8 mice per cage continued to day 7. There were no significant differences in specific lymphocyte subpopulations observed among these groups. The results of this study suggest that a population density of 4 mice per cage induced minimal stress compared to that induced by the population densities of 2 or 8 mice per cage. Since stress is known to induce alteration in a variety of biological functions, the population density of mice per cage should be considered in the interpretation of research data.
authors: Department of Comparative Medicine, College of Medicine, Milton S. Hershey Medical Center, Pennsylvania State University, Hershey 17033.
authors: X
authors: X
authors: Peng
authors: C M
authors: CM
authors: Lang
authors: C K
authors: CK
authors: Drozdowicz
authors: B M
authors: BM
authors: Ohlsson-Wilhelm
mesh_terms: D000818:Animals; D003345:Corticosterone / Q000097:blood*; D003441:Crowding; D006799:Housing, Animal; D007958:Leukocyte Count / Q000662:veterinary; D008214:Lymphocytes; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C / Q000097:blood*; D011156:Population Density; D011897:Random Allocation
chemical_list: D003345:Corticosterone