Cellular immune responses of nutritionally stressed juvenile cotton rats (Sigmodon hispidus) during acute benzene exposure

Abstract

Wild juvenile cotton rats (Sigmodon hispidus) were used in this study to examine the effects of exposure to cyclophosphamide (CY) or differing levels of benzene on selected measures of cellular immunity following dietary protein restriction. Benzene caused marginal immunotoxicity as indicated by suppressed splenocyte proliferation and total circulating neutrophils. Cyclophosphamide and also crude protein restriction induced severe immune lesions manifested as thymus and spleen atrophy, depressed delayed hypersensitivity response, reduced proliferative capacity of splenocytes, and reduced numbers of total leukocytes, lymphocytes, and splenocytes. Although severe immune modulation resulted from the individual effects of CY exposure and dietary protein restriction, there was little statistically significant toxicant-diet interaction.

Immunotoxicity of Jet Fuels and Solvents

“…The human data are comparable to animal studies documenting compromised T-and B-lymphocyte function after exposure to benzene (Wierda et al, 1981;Robinson et al, 1997). McMurry et al (1994) published results in which rats ip injected with benzene did not exhibit T-and B-cell dysfunction, possibly because the animals were sacrificed nine days after the last exposure, giving time for the benzene to metabolize and for recovery, whereas the Robinson et al (1997) study euthanized rats within three hours after the final exposure. Selective B lymphocyte suppression with benzene exposures can also possibly due to the short life span of B cells (Aoyama, 1986).…”

Protein Nutrition of Southern Plains Small Mammals: Immune Response to Variation in Maternal and Offspring Dietary Nitrogen

“…Although cotton rats are able produce young under suboptimal conditions, the immune system of these young may be compromised (McMurry et al 1994a(McMurry et al , 1994b, and the date of first estrus may be delayed . Some evidence suggests that the presence of high-protein forage (dicots, insects, and seeds) allows cotton rats to maximize their growth potential, resulting in high-density populations (Shetter et al 1998).…”

Indicators of Immunotoxicity in Populations of Cotton Rats (Sigmodon hispidus) Inhabiting an Abandoned Oil Refinery

“…Although speculative, this trend may in part be a function of increased stress levels in cotton rat populations due to seasonally high population densities (Christian et al, 1965;McMurry et al 1994b). Possible synergistic interactions between chemical stressors and seasonally variable extrinsic and intrinsic stressors such as climate, nutrition, reproduction, and density could enhance otherwise benign toxic effects.…”