TUNEVALL AND LINDNER 



bacterial defense of the body, as antibody formation (Lindner and 

 Tunevall, 1958) leucooytotic reaction (Fedor etal., 1958; Helmsworth 

 et aU, 1955; Villalobos etal., 19 55), phagocytosis (Fedor et al,, 1958) 

 or local tissue reactions (Beyer, 1956; Sanders etal,, 1957; Szilagyi 

 et al,, 1956). As early as 1897, Fischl observed fatal septicemia in 

 rabbits subjected to chilling. 



More recently, the possibility of bacteremia has been studied by 

 Fedor et al, (1956) in dogs maintained at 28° C to 29° C for 6 to 12 

 hours. In such animals no endogeneous bacteremia occurred, and 

 the ability to clear the blood stream from injected bacteria was very 

 slightly impaired. On the other hand, Dillingham (1957) observed in 

 extreme hypothermia an increased passage of bacteria through the 

 endothelial lining of the gut. Having observed at autopsies of mice 

 subjected to prolonged hypothermia the frequent occurrence of peri- 

 tonitis and bacteremia, we have undertaken some experiments in 

 order to study more closely the development of these conditions and 

 to establish their importance for the mortality of mice kept in the 

 hypothermic state. Further, as a complement to this study, an in- 

 vestigation of the ability of hypothermic mice to eliminate injected 

 bacteria from the blood stream was undertaken. 



METHODS 



Inbred albino mice weighing 15 to 20 gmwere used for the experi- 

 ments. The procedure for bringing mice into a controlled hypother- 

 mic state and maintaining them there has been described in a 

 previous paper (Lindner and Tunevall, 19 58) and will not be repeated 

 here in detail. Briefly, the animals were pre- treated with chlor- 

 promazine-HCl (Hibernal) and ethyl- (1- methyl-butyl) -malonyl- car- 

 bamide- Na (Nembutal) before being immersed into a water bath 

 where they were, under administration of oxygen, kept at a body 

 temperature of 22° C (registered rectally). 



Intravenous injections were made into the dorsal vein of the tail 

 with a No. 20 "Record" cannula on a syringe of the tuberculin type. 



240 



