EFFECT OF IHKADIATIOX OX HE.MIX FORJLA.TION 625 



labelled ferric chloride only that due to /3j-globiilin was found to be 

 radioactive. 



How the turnover rate of the circulating plasma iron is influenced 

 by interference with hemopoietic processes going on in the human and 

 animal organism was investigated in numerous cases by John Lawrence 

 and his colleagues and several others. 



Being interested in the problem of radiation anemia we determined 

 the rate of disappearance of labelled plasma globulin from the circulation 

 of rabbits exposed to Roentgen rays and the incorporation of ^^Fe into 

 the circulating hemoglobin and into marrow hemin of guinea-pigs and 

 rabbits. The effect of irradiation on the incorporation of ^ape into the 

 red corpuscles of the rabbit and of the rat was previously investigated 

 by Huff, Henessy and their associates^^'^\ 



In view of the marked effect of irradiation on the incorporation of 

 ^^Fe into hemoglobin we wished to know if hemins formed in another 

 milieu than the bone marrow are affected by irradiation as well. We 

 investigated therefore the effect of exposure to radiation on the incor- 

 poration of ^^Fe into the iron containing enzymes of the liver and into 

 cytochrome c and myoglobin of the muscles. In this note results obtained 

 in the investigation of cytochrome b (Strittmatter^^^^) of the liver and 

 that of myoglobin are communicated. 



EXPERIMENTAL 



In 21 experiments with guinea-pigs an aggregate number of 220 animals, 

 weighing 450—700 gm, were injected intraperitoneally with 0.2—0.4 ml of sahne 

 containing 2 to 7 /ugm of with^^Fe labelled iron of 1/2 — V4 /^Curie activity. Half 

 of the guinea-pigs was exposedto X-rays (160 kV, 43 rper min for 10 to 33 minutes). 

 Injection took place 15 to 300 min following exposure. No food was administered 

 during the experiment. 



The animals were killed 4 to 48 hrs later, their livers homogenized in sucrose 

 and fractionated as described by Hogbein and Schneider. Ferritin was extrac- 

 ted both from microsomes and from the supernatant, cytochrom b hemin from 

 microsomes (Loftfield^^)) and catalase from the supernatant. Total iron, cyto- 

 chrome c and myoglobin iron were furthermore isolated from the muscles making 

 use of the method of Theorell and Akeson^'^). 



Ferritin was piecipitated from the supernatant by addition of half volume of 

 ammoniumsulf ate . The precipitate was taken up in water and repeatedly fractio- 

 nated with ammoniumsulf ate. The precipitate was then taken up in water, 

 heated to 70° C for a few minutes and centrifugcd after cooling. The supernatant 

 ferritin was found to contain 17 to 20% iron. 



The microsomes were homogenized in water, the pH adjusted to 5 and centri- 

 fuged after the lapse of 30 minutes. The precipitate was oncie more homogenized 

 and washed with water. All the microsome ferritin was found to be in the water 

 phase. The insoluble particles contained the cytochrome b and some protein- 

 bound iron. The cytochrome b hemin was extracted from this fraction with a 

 mixture of acetone and HCl (10 ml 20% HCl in 1 htor of acetone). The acetone 



40 Hevesy 



