LONG TERM LIVER RADIATION DAMAGE IN THE RAT FOLLOWING INTERNAL AND EXTERNAL IRRADIATION

Summary Liver radiation damage has been assessed and compared in the rat following two different liver irradiation regimes. (i) One group of rats received liver radiation doses ranging from 4,250 rads to 8,500 rads delivered externally in fractionated doses over 11 days by a 240 kV X‐ray machine. Liver damage was assessed by determining serum levels of alanine aminotransferase, aspartate aminotransferase and total haemolytic complement. (ii) A second group of rats received a liver radiation dose of 8,500 rads delivered internally via intravenously injected radioactive colloidal gold–198, and similar serum parameters were studied. Liver histology was also carried out on both groups of rats. Both treatments result in abnormal serum levels of enzymes and complement, and a comparison of results for both irradiation regimes indicates that, while there are slight differences in early response, particularly in serum complement levels, nevertheless similar long term liver damage results.