INCORPORATION OF >'C INTO TISSUE 



813 



EXPERIMENTS OF VERY SHORT DURATION 



As we wished to obtain information on the possible effect of irradiation 

 on the rate of resorption of intraperitoneally injected acetate, we killed 

 the mice in a few experiments 5 to 15 minutes only after the injection 

 took place. 0.1 ml of saline containing about 10^ counts/min of labelled 

 acetate was injected to groups of 4 mice. In contrast to all other experi- 

 ments, in these experiments of very short duration food, not, however, 

 water, was withheld from the mice after irradiation. 



As seen in Table 6a the i*C content of the blood of the irradiated and 

 non-irradiated mice does not differ much. By adding to half of the blood 

 secured 0.5 ml of 2-n HCl and drying the blood in vacuo, a process which 

 was repeated, we removed the carbonate content of the blood. In the 

 5 min experiments this procedure lead to a diminution of the blood 

 activity by 25 to 27 per cent for the non-irradiated blood and by 28 

 to 45 per cent for the irradiated blood. 



The figures of Table 6a do not indicate a depressed resorption after 

 irradiation. Irradiation depressed in these experiments ^^C incorporation 

 into liver fats, in the 5, 15 and 30 min experiments by 56, 67 and 45 per 

 cent respectively. Liver fat figures show as in the other experiments 

 described very fluctuating values. 



EFFECT OF IRRADUTION ON SUCKLING RATS 



The summary of a few experiments carried out with 7 to 14 day old 

 rats which had access to food, except for the 3 min which irradiation 

 has taken, is seen in Table 7. 



In an experiment with 34 suckling rats, weighing 40 gm, the animals 

 had no access to food for the 4 1/4 hr which elapsed between injection 

 with acetate and the killing of the rats. Injection took place after irra- 



Table 6o. — Effect of Irradiation on Mice Killed a few Minutes afteb 

 Administration of Labelled Acetate 



