Chapter 12 



EFFECT OF NEUTRON IRRADIATION ON PROTEINS OF 



SONICIZED BONE MARROW AND BLOOD 



PLASMA OF RABBITS 



By LAURA E. KREJCI, JAMES L. LEITCH, and LUCILE SWEENY 



INTRODUCTION 



Since neutron irradiation of rats (1 ) brings about a decrease in the leuko- 

 cyte and erythrocyte counts indicative of some effects on the leukopoietic 

 and erythropoietic systems, it was deemed advisable to determine whether 

 or not neutron irradiation produces any changes in the proteins of bone 

 marrow. Although considerable data are available in the literature on the 

 cellular constituents of bone marrow, both normal and pathological, little 

 is known concerning the protein constituents of this organ. Miiller (2) 

 and Keilhack (3) have reported data, obtained by salt precipitation meth- 

 ods, on the protein distribution in the bone marrow of rabbits (summarized 

 in Table I). 



Inspection of Table I indicates wide differences in the results obtained 

 by Muller and Keilhack. Keilhack showed that only a portion of the 

 fibrinogen in bone marrow is removed by the short period of extraction 

 used by Muller. The values found for iibrinogen by Keilhack were ob- 

 tained only when the buffered saline solution was left in contact with the 

 ground bone marrow for at least 24 hours. These data must therefore be 

 considered more reliable than those of Muller. However, both sets of 

 results are open to the criticism that they are based apparently on the 

 values found for the total protein of the extract and not of the oi-iginal 

 sample of bone marrow. It is therefore evident that the data in the liter- 

 ature are of questionable significance with regard to the protein distri- 

 bution in bone marrow. 



MATERIALS AND METHODS 



Animals. Rabbits were chosen as the experimental animal because of 

 the large amount of bone marrow obtainable and the greater ease with 

 which both blood and bone m.arrow could be obtained. Four rabbits, 

 referred to as A, B, C^ and D, respectively, were used and kept under 

 observation for periods ranging from 14 to 110 days. A fifth rabbit, E, 

 was an extra animal that had previously been used in the laboratory as a 

 source of normal blood and was not studied by the authors prior to the 

 time of its use. 



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