Effects of Crowding of Mice on Humoral Antibody Formation and Protection to Lethal Antigenic Challenge

Abstract

The effects of grouping (crowding) on humoral antibody response to typhoid paratyphoid vaccine and subsequent protection from a minimal lethal challenge dose of Salmonella typhimurium were studied in white Swiss-Webster mice. The data show a trend between the degree of crowding and antibody response. Geometric mean titers of high density grouped mice were significantly lower than the geometric mean titers of the less crowded mice. Also, there were significantly less antibody responders in the high density grouped mice than in the less crowded mice. However, challenged with a minimal LD50 dose of Salmonella thphimurium, no deaths occurred in the immunized study group, regardless of measurable antibody level. In the nonimmunized controls, which were under the same stressor conditions, there was a significant difference between the level of crowding and death to challenge. The data show that nonimmunized mice in this study exhibited a marked increase in susceptibility to an infectious agent when under the stressor effect of crowding.

Psychological Stress, Neuroimmunomodulation, and Susceptibility to Infectious Diseases in Animals and Man: A Review

“…As early as 1890, Charrin [66] noted that forced physical exercise (a physical stressor) was associated with an increase in the mortality of rats infected with Bacillus anthracis. The same stressor appears to increase mortality in rabbits infected with Streptococcus pyogenes [67] and in rats infected with Mycobacterium tuberculosis [70], With mice, exposure to physical (cold) [68,69] or psycho logical (crowding) stressors [72] increases the mortality of animals infected with Salmonella typhimurium. In ponies too, resistance to this bacterium appears to be influenced by stressors of a prevalently physical type.…”

“…Edwards and Dean [72] studied the effects of psycho logical stress on humoral immune response to an extracel lular bacterium. Their experiment showed that, in mice infected with Sal.…”

Population density and growth rate in laboratory mice

“…For example, Les (1972)recorded tail lesions in C3H/HeJ mice, and noted that these were related to population density, though this is difficult to quantify from the data given in his paper. Edwards and Dean (1977) showed a reduction in antibody formation with extreme crowding (down to 8 cm 2 /mouse) with a density-dependent increased sensitivity to challenge with Salmonella typhimurium in unimmunized, but not immunized mice. Stocking density may also affect physiological variables.…”

Crowding in Prison: The Relationship Between Changes in Housing Mode and Blood Pressure

“…Calhoun has noted the dissolution of maternal ties, homosexuality, and social withdrawal in rats when the population is allowed to increase in confined space (2)(3)(4). Secretions of the adrenal medulla and adrenal cortex have been related to crowding in animals (5), and crowding may also have a negative effect on humoral antibody formation (6).…”