Chapter 9 



THE EFFECT OF NEUTROX RADIATION ON THE PEROXIDASE 

 AND CATALASE ACTIVITY OF BONE MARROW 



By GLADYS E. WOODWARD 



Bone marrow from the leg bones of rabbits and dogs, removed at death 

 of animals treated in connection with other phases of this radiation project 

 (1), has been investigated for its peroxidase and catalase activity. 



The determination of peroxidase is complicated by the presence of 

 hemoglobin and catalase in whole marrow. Therefore, in the present 

 study, washed marrow has been used, the washing eliminating all of the 

 hemoglobin and that part of the catalase which is present in the red blood 

 cells. The method of Schwimmer (2), which measures peroxidase by its 

 catalytic effect on the reaction between HoO? and KI, has been applied 

 to the washed bone marrow. Since catalase also acts upon H2O?, its pres- 

 ence interferes with the estimation of peroxidase by reducing the concen- 

 tration of H2O2 available for the peroxidase reaction. Unless catalase is 

 present in considerable excess, however, the error in the peroxidase value 

 is only slight. 



PROCEDURE 



Marrow was removed from one to three bones, weighed and mixed with 

 9 parts of water to give a 1 : 10 suspension. By gentle agitation, the red 

 blood cells present were easily broken up and the hemoglobin removed 

 in the supernatant fluid by centrifugation. The washing was repeated 

 until the marrow sediment became free of hemoglobin. The 1:10 sus- 

 pension of washed marrow was then homogenized by submitting to intense 

 vibrations of 10.5 kc. provided by a Pierce magnetostriction oscillator 

 of the Chambers and Flosdorf type (3). During treatment, 5 to 7 cc. 

 aliquots, which were subsequently mixed, were placed in a 10 cc. Pyrex 

 beaker which was fixed at about 1 mm. above the top of the vibrating 

 nickel tube. Water, contained in a water jacket, was the medium between 

 nickel tube and beaker. The duration of treatment was from 5 to 10 

 minutes depending upon consistency of the tissue. The homogenized 

 mixture was used for the peroxidase and catalase estimations. 



In the estimation of peroxidase, 1 the quantities of the Schwimmer (2) 

 method was used. To a mixture of 10 cc. reagent (containing 0.027 M KI, 

 0.001 :\I XaoSzOo, 0.1 per cent starch, and 0.02 M acetate buffer of pH 4.7) 

 and ^•arying amounts of homogenized marrow suspension diluted to 2.25 



74 



