Whole-body inhalation exposure to 1-bromopropane suppresses the IgM response to sheep red blood cells in female B6C3F1 mice and Fisher 344/N rats

Abstract

1-Bromopropane (1-BP) is categorized as a high-production-volume chemical and is currently used in the manufacture of pharmaceuticals, pesticides, and other chemicals. Its usage is estimated to be around 5 million pounds per year, resulting in the potential for widespread exposure in the workplace. Case reports and animal studies have suggested exposure to this compound may cause adverse reproductive and neurological effects. Using a battery of immunological assays, the immunotoxicity of 1-BP after whole body inhalation exposure in both mice and rats was evaluated. Significant decreases in the spleen immunoglobulin (Ig) M response to sheep red blood cells (SRBC) were observed in both mice (125–500 ppm) and rats (1000 ppm) after exposure to 1-BP for 10 wk. In addition, total spleen cells and T cells were significantly decreased after approximately 4 wk of 1-BP exposure in both mice (125–500 ppm) and rats (1000 ppm). No change in natural killer (NK) cell activity was observed. The observed alterations in spleen cellularity, phenotypic subsets, and impairment of humoral immune function across species raise further concern about human exposure to 1-BP and demonstrate the need for additional investigations into potential adverse health effects.

Keywords::

• Immunotoxicity
• inhalation
• humoral immue response
• 1-BP

Acknowledgments

This research was supported in part by the Intramural Research Program of the NIH, National Institute of Environmental Health Sciences, and by an interagency agreement with the National Institute of Occupational Safety and Health (Y1-ES-001). The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the National Institute for Occupational Safety and Health.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.