Changes in the liver function and morphology after repeated local action of γ-rays Co60 on the upper right quadrant of the abdomen

In experiments on rabbits, the entire liver area (6 cm x 10 cm field) was irradiated at focal doses of 200, 3O0, 400 or 500 rad, and a part of the liver area (3 cm x 5 cm field) at 600, 1000 or 1500 rad, up to a total dose of 6000 rad. Apart from the liver, the field inevitably included the adjacent part of the stomach and intestines and the underlying soft tissue. During irradiation of the liver area using a maximum of 200 rad to a total dose of 6000 rad, only the protein function of the liver was found to be affected, while at 300 rad all the liver functions studied were disturbed. However, these changes were not prolonged. The 400 rad dose (in irradiating the entire liver area to a total dose of 6000 rad) can be regarded as representing the maximum tolerance level, since there irreversible changes occurred leading to the death of the animals. For partial irradiation of the liver, this level was 600 rad. The animals first exhibited slight leucopenia, disturbed excretory function and lowered alkaline phosphatase activity. At the peak of the disorder there was a still greater fall in the leucocyte count, and erythropenia and thrombopenia developed; the animals became sluggish, refused food, lost considerable body weight, and some of them died. Liver function studies showed further deterioration of the excretory function, reduction in the total protein concentration, disturbance in the ratio of the protein fractions of the blood serum and profound disturbance in the antitoxic function of the liver. Morphological examination revealed destruction of the greater part of the hepatocytes, lysis of their nuclei, de-complexing of liver proteins and focal necroses of the parenchyma. In the surviving animals the disturbed functions were restored at the end of the second or the beginning of the third month after the completion of irradiation. (author)