NEUTRON EFFECTS ON ANIMALS 



71 



enzyme level in a period up to 17 days after exposure. A'alues for each 

 animal in both the pre- and post-irradiation periods varied between 45 and 

 ()0 one-hour units per 100 cc. of serum. 



SERUM ALKALINE PHOSPHATASE ACTIVITY IN DOGS 



Several determinations of serum alkaline phosphatase activity were 

 made on dogs before and after exposure to neutron radiation. These ani- 

 mals were those used in a study in this Laboratory on the effects of large 

 doses of neutrons (7). The phosphatase data have been listed in Table II. 

 It is seen that a dose of 400 n given over a period of four days resulted in an 

 increased enzyme level; on the sixth day after completion of the irradiation 



TABLP: II 

 The Effect of Neutron Radiation on Serum Alkaline Phosphatase Activity in Dogs 



* The total dose consisted of 115 n on each of three successive days; and a dose of 

 55 n on the fourth day. Box Xo. 4 was used (8). 



t Two-hour units per 100 cc. serum. ' 



the activity in serum may reach a value which is 3 to 6 times that found 

 before exposure. It is to be noted that the severe irradiation procedure 

 here employed caused the death of three of the four animals in to 8 days; 

 dog No. 4 was killed on the seventh day (7). 



DISCUSSION 



The preliminary nature of the data presented in this study warrants few 

 definite conclusions. It is possible, however, to point out several aspects 

 which appear to be of interest in connection with the further investigation 

 of the effects of neutrons on serum alkaline phosphatase activity. If the 

 enzyme decrease in rats, as shown in Table I, is considered, it is fo\ind to 



