Role of Gram-Negative Bacteria and Their Endotoxins in Rat Death after Heat Stress,
Abstract
Stress which induces an increase in the gram-negative bacterial count of the upper intestinal tract can be associated with extra-intestinal invasion of gram-negative bacteria and their endotoxins. The Limulus amoebocyte lysate (LAL) test and standard microbiological procedures were used to determine if duodenal and extra-intestinal invasion in rat heat stress. Because gram-negative bacteria were found in extra-intestinal tissues (lung, liver and spleen) of some non-heated controls of the first rat group studied, the experiments were repeated in rats found to be free of extra-intestinal gram-negative bacteria (group II). After heat stress, short and intermediate survivors of group I had a significantly increased incidence of duodenal invasion as compared to controls. Intermediate survivors also had extra-intestinal invasion (a significantly increased incidence of gram-negative bacteria or endotoxins in liver, spleen or blood). Short and intermediate survivors of group II had duodenal, but not extra-intestinal invasion. No significant differences in the mean survival times of groups I and II were found. Duodenal invasion did occur after heat stress. This did not result in extra-intestinal invasion in group II and even the extra-intestinal invasion noted in group I had no significant impact on length of survival. Therefore, extra-intestinal invasion of gram-negative bacteria and their endotoxins did not appear to play a mediating role in rat death after heat stress.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 26, 1981
- Accession Number
- ADA111076
Entities
People
- D. A. Dubose
- J. Rowlands
- K. Basamania
- L. Maglione
Organizations
- United States Army Research Institute of Environmental Medicine