NUCLEIC ACID IX RETROGRADE SARCOMATA 



741 



Table 7. — Colchicine Treated Rats 



Specific Activity of Desoxyribosenucleic Acid expressed in Percentage of the Specific 

 Activity of the Inorganic P from the .sarcomata and plasma: 



(e) 50 y colchicine were administered both 7 days before, and 3 days 

 before the injection of labelled phosphate. Weight of rats was 97 and 

 135gmresp.atthe start, 105 and 150 gm at the end of the experiment. 

 Weight of sarcomata 5 and 4 gm resp. with hard necrotic inclusions. 



The results obtained are seen in Table 7. 



The mean value obtained for the extent of renewal of desoxyribose- 

 nucleic acid in the colchicine treated rats is about ^s lower than the 

 corresponding value for the controls (cf. Table 3) ; the individual values 

 vary greatl3^ The variation in the "plasma scale" is less than it is in the 

 "sarcoma scale", thus indicating a somewhat enhanced phosphate 

 permeabily of the sarcomata in colchicine treated rats. 



In some of our experiments, we studied the combined effect of Roentgen 

 radiation colchicine injection on nucleic acid foriration. Table 8 denotes 

 an experiment in which 



(a) Colchicine was administrated 1 day before the injection of 32p. 



(b) Colchicine was administered; the following day the rat was irra- 

 diated with 30 r per minute for 10 minutes, ^^p then injected and the rat 

 killed 2 hours later. 



(c) The same procedure was followed as in (b), but without colchicine 

 treatment. 



(d) The experimental conditions were those of (b) with the sole excep- 

 tion that the rat was irradiated with only 15 r per minute, for 10 min. 

 The results obtained were seen in Table 8. 



The combined effect of colchicine and X-rays is, as shown by the 

 above figures, no greater than is the effect of X-rays alone in influencing 

 the turnover rate of desoxyribosenucleic acid of the sarcoma. In view 



