Cis-DDP has been used as a radiosensitizer in combination treatment modality for malignant tumors. Of which mechanism is uncertain uncertain. The effects of combined Cis-DDP and irradiation on number of tumors have been studied in vitro and in
vivo. The
effects of combined Cis-DDP and irraadiation on the liver are important. Because the liver is a radiosensitive organ and frequently exposed to irradiation during treatment for intra-abdominal malignancies. But the studies of combined Cis-DDP and
irradiation on the liver have not been reported.
So this study was performed to see the effect of Cis-DDP in combination with radiation on the liver. Total 66 Sprague-Dawley rats were divided into 5 groups ; control, Cis-DDP(2.5 mg/kg) administration, radiation (6, 8, 10Gy, respectively), and
combined
Cis-DDP and radiation, which consisted of pre-and post-administration of Cis-DDP Light and electron microscopic examination was performed 30 days after each experiments.
Cis-DDP administration induced mild congestion and focal hemorrhage in hepatic lobules with focal necrosis and degeneration of hepatocytes. Electron microscopic examination showed irregular cytoplasmic organelles and chromatin clumping in
hepatocytes.
In radiation treatment group, hemorrhage of hepatic lobules, necrosis and degeneration of hepatocytes, edema and inflammation in portal tracts were aggravated with increased dosage of radiation. Hepatic lobular disarray and inflammatory cell
infiltration in portal tracts were noted from 8 Gy radiation. Vacuoles and electron dense bodies as well as swollen mitochondria in hepatocytes were frequently noted on electron microscopic examination .With combined treatment, all the light and
electron microscopic changes were more severe than radiation alone regardless of sequence of Cis-DDP administration and lobular disarray and inflammation in portal tracts were started to note with 6 Gy radiation When the hepatic lobular disarray
and
inflammation in portal tracts were used as end-points, the enhancement ratio of Cis-DDP was 1.3 in normal rat livers.
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