786 



ADVENTURES IX RADIOISOTOPE RESEARCH 



A comparison of the phosphatase activity of the serum of normal and 

 of sarcoma rats leads as recorded in Table 2 to the result that in several 

 cases the activity of sarcoma rat plasma is lower than that of controls 

 but that the difference is not pronounced, the mean values for the 

 percentage phosphate split off being 41.9 and 34.7 respectively. 



EFFECT OF ADDITION OF MAGNESIUM ON THE PHOSPHATASE 



ACTIVITY 



In the first set of experiments (I) 0.192 mgm nucleic acid were dissol- 

 ved in 4 ml serum, in the second set (II) 1 mgm in 1 ml plasma. MgSO^ 

 was then added amounting to 0.001 mol. per liter. As it was to expect 

 the addition of magnesiumsalt leads to an increased spliting off of in- 

 organic phosphate. However, as seen in Table 3 the effect observed is 

 not very pronounced and is larger in the experiments in which more 

 substrate was used. 



Table 3. 



Effect of Magnesitjm on the Phosphatase Activity 



Addition of 0.012 ml of 0.1 molar NaF to each ml serum was without 

 effect on the formation of inorganic phosphate or of organic acid-soluble 

 phosphorus compounds. The centrifugate contained 53.5 and 53.5 per 

 cent of the total ^^P added as nucleic acid as inorganic P after the lapse 

 of 8 hours without addition of fluoride, while 53.6 and 55.0 per cent 

 were found when fluoride was added. The figures for the total acid- 

 soluble P were 60.9; 60.7 and 61.9; 61.0 resp. 



Nor had addition of 0.1 ml 0.02 molar Na2HAs04 to each ml serum 

 containing 0.16 mgm nucleic acid any pronounced effect. 



EFFECT OF INTESTINAL MUCOSA EXTRACT ON NUCLEIC ACID 



The intestinal mucosa extract used in our experiments was prepared 

 from rats' intestine. The mucosa tissue was suspended in 5 parts of 87 

 per cent glycerin solution and shaken for an liour. One hundredth volume 

 of 10 jier cent NaOH was then added and the extract kept at room tem- 



