Effects of Host Fighting Behavior on the Course of Infection of Trypanosoma Duttoni in Mice

Abstract

In one experiment, male albino mice were inoculated with Trypanosoma duttoni, and were allowed to begin fighting on the same day; the fighting animals developed significantly lower parasitemias than the isolated controls throughout the reproductive phase of the infection. In two other experiments, mice were allowed to fight for a period of 10 days prior to inoculation; the fighting animal exhibited higher parasitemias than the controls, with the subordinate mice developing slightly, but not significantly, higher parasitemias than the dominant animals. Since all differences noted among controls, dominants and subordinates were during the reproductive phase of the infection, and since no differences were observed in the length of infection among these groups, it was concluded that fighting altered the ablastic, but not the trypanocidal antibody response. This alteration is believed to have resulted from the action of adrenal cortical hormones on antibody—producing cells. Sustained elevation of plasma corticosterone levels during 10 days of fighting in the latter experiments may have been responsible for the different results obtained with the two experimental designs.