TUNEVALL AND LINDNER 



The effect of tetanus toxin on mice subjected to low environ- 

 mental temperature was studied by Ipsen (1951). The survival after 

 large toxin doses was prolonged in chilled animals, whereas sub- 

 lethal doses caused more deaths in chilled mice than in those kept 

 at normal room temperature. Increased susceptibility to endo- 

 toxins from Gram- negative bacteria of mice held at 5° C and 15 C, 

 when compared to animals at room temperature was found by 

 Previte and Berry (in press). In hypothermia induced so as to avoid 

 stress reactions, no effect on the hematologic or histologic mani- 

 festations of staphylococcal exotoxin in rabbits was found by 

 Cole (1960). 



EXPERIMENTAL 



Material and Methods 



Albino mice weighing 20 to 40 gm were numbered serially. The 

 allotment of animals to different experimental groups was done by 

 a random method according to the tables of Fisher and Yates (1953). 



For inducing hypothermia the following procedure was used: A 

 subcutaneous injection of 32 mcg/g body weight of Chi orpromazine- 

 HCl is followed after 30 min. by an intraperitoneal injection of half 

 this amount of ethyl- (1- methyl-butyl) -malonyl- carbamide- Na. The 

 mice are then, in their narcotized state, fixed onto suitably formed 

 lead plates with adhesive tape and immersed in a supine position 

 into a 21° C water bath with only the head and part of the thorax 

 above the water. The rectal temperature will be stabilized within 

 one hour between 21.5° C and 23.5 C, and the temperature in 

 lower esophagus will be stabilized about 0.5° C higher. Oxygen and 

 carbogen are administrated continuously to the chamber formed by 

 the water bath and its fairly tightly closed cover. 



Rewarming starts with slowly raising water temperature to 33° C 

 over a 4 to 5 hour period. When they begin to show activity, the 

 mice are freed from the lead plates, dried, transferred to their 



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