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mals. Under these circumstances the specific activity of inorganic ortho P, 

 acid labile P, 7-rninute hydrolyzable P, and total acid soluble P was reduced by 

 irradiation. Except in the acid labile fraction, there was no significant change 

 in the specific activities of these fractions fronn muscle taken from animals in- 

 jected 60 minutes after irradiation instead of immediately afterwards. The spe- 

 cific activity of acid labile phosphate appeared to be approaching the control val- 

 ue in the 60-minute experiment. 



In in vitro experiments with irradiated liver, small increases of the 

 order of 5 to 1 percent were observed in inorganic o-phosphate, acid labile phos- 

 phate, and 7-minute hydrolyzable phosphate. I doubt if these differences are 

 significant. These data suggested to us that the effect of irradiation on the liver 

 was being influenced by the effect of total-body irradiation. 



POTTER: Before I would accept that conclusion, I should like to know 

 how well the inorganic p^^ in the medium equilibrated with the acid soluble pool 

 of these slices in the controls. 



SHERMAN: These were incubated for an hour. I cannot answer your 

 question except to say that we had a high specific activity of inorganic phosphor- 

 us from our tissue slices. There were about Z \ic. of p3Z/ml. in the medium 

 and this was enough to give high rates in all the fractions, so that a lot of P^^ 

 was taken up. I don't know whether or not this was equilibrated because these 

 studies were done only at 60 minutes. 



POTTER: Even with liver slices of 0. 5 mm. thickness, glycogen was 

 formed only in the few cells on the outside of the slice according to the studies 

 by Buchanan and Hastings. Inorganic P^^ may equilibrate with some ATP in the 

 outer cells of the slice, and then, of course, when you go ahead and do the re- 

 mainder of the experiment, you have some odd ATP. 



SHERMAN: These samples were washed repeatedly and I don't think 

 there was very much inorganic phosphorus hanging on. 



POTTER: No, I don't mean that. 



BENNETT: You would have to express this as a ratio of the activity 

 of what you had in the external medium and inside and in ATP to enable you to 

 evaluate it properly. 



SHERMAN: This still would not satisfy Dr. Potter's objection. 



DUBOIS: The animal studies indicated only turnovers in the total 

 quantity of acid labile phosphorus in the control and in the irradiated tissue. 



SHERMAN: There is not much difference in the total quantity of acid 

 labile phosphorus between the control and irradiated animals. 



BENNETT: I don't think this varies appreciably. 



DUBOIS: It has been our impression from analysis of total concentra- 

 tion that there isn't any appreciable change in the total inorganic phosphorus in 

 the irradiated liver, and I wonder whether you agree with this. 



SHERMAN: I think that there is no appreciable change in the total 

 quantity of inorganic P. I am not sure that I would agree that there is not a 

 change in the total acid soluble P. 



