248 



E. Y. GRAYEVSKY, et Cll. 



method in some organs (Konstantinova and Grayevsky, 1960). These 

 exijeriments should determine whether the protection is always re- 

 lated to hypoxia and whether all forms of hypoxia are capable of pro- 

 viding protection. 



The following results were obtained in the experiments : 



1. Some protective effect of hypothermia is observed for the first 

 time at a rectal temperature of 18 to 20°C; this effect increases with 

 temperature decrease down to 6 to 8°C and is accompanied by a dimi- 

 nution of 02-tension in the spleen and the liver by 15 per cent as com- 

 pared to the initial level (Konstantinova, 1960, and Fig. 7). 



2. Substances blocking the transport of oxygen by haemoglol)in 

 (CO, NaN02) exert a distinct protective effect which depends on the 



O 



o 



_o 



en 

 O 



E 



u 

 a 



80 



A. CO 



0-5 vol. percent 



Air 



Q_ 



30 60 90 120 



Time after injection (mm) 



Fig. 8. (a) — 1, dependence of a survival of mice y-irradiated with 900 r of 6"Co (600 r 

 per minute) upon exposure to carbon monoxide (0-5 vol. per cent) followed by air. 

 2, 02-tension (percentage of the initial level) in the spleen. 3, in the liver and CO-Hb 

 content in irradiated mice under the same conditions. 



(b) — 1, survival of mice y-irradiated witli UOO r at various time inter\als after injection 



of NaN02. 2, 02-tension in the spleen. 8, in tlie liver. 4, Mt-Hb content in non-irradiated 



mice at a corresponding time interval after injection. 



