416 ADVENTURES I\ RADIOISOTOPE RESEARCH 



part of the upper curve is presumably due to an increase in the activity 

 of the protein fraction, which as shown by the lower curve is increasing 

 with time. 



d) Skin and Heart Muscle 



For the skin and heart muscle we determined the effect of DP. P. 

 injection on i^Q incorporation into the total tissue only. The curves 

 plotted in Fig. 6 (a) representing the results obtained for the skin, show a 

 similar trend to the corresponding curves obtained for the skeletal muscle. 



The first part of the curves which show ^^C incorporation into the 

 heart tissue 6(&), indicates an accelerated rate of i^C incorporation into 

 the total organ under the effect of D.P.P. administration. The further 

 trend of the figures is quite complicated, which may be due at least 

 partly to the fact that we deal with the total tissue which contains fat 

 and acid soluble fractions of appreciable i^c content and less active 

 protein and glycogen fractions. 



The trend of the curve denoting the change in the specific activity of 

 the heart muscle tissue under the effect of D.P.P. markedly differs 

 from that of the curves obtained for the skeletal muscle. This difference 

 suggests a specific effect of D.P.P. on the heart. 



Summary 



The rate of incorporation of i*C after injection of earboxyl labelled acetate 

 in the liver, brain, skin, skeletal and heart muscle of control mice is compared 

 with the values obtained with organs of mice to which dinitro-cyclo-pentylphenol 

 (D.P.P.) was administered. 



Administration of D.P.P. increases the rate of incorporation of i*C into hver 

 fat and total liver tissue in the first 10 minutes of the experiment and decreases 

 in the later part. Such a behaviour is expected if D.P.P. increases the rate of ace- 

 tate metabohsm in the liver. 



Administration of D.P.P. has a slight effect only on i^C incorporation into 

 brain fat or total brain tissue. 



The D.P.P. injected mice take up less "C in the skeletal muscle tissue and 

 skin tissue than do the controls. 



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