Role of free radical scavengers in pancreatic carcinomas of hamsters.

The involvement of free radicals in the carcinogenic mechanism has been suggested, however, little is known about the role of free radicals in the pancreatic cancer. In this study, the effects of active oxygen on the carcinogenesis of the tumor were examined by measuring the levels of scavengers in pancreatic cancer of Syrian golden hamsters. Pancreatic cancer was induced by di-iso-propanol nitrosamine (500 mg/kg body weight/week x 24 weeks). Activities of superoxide dismutase (SOD), catalase, glutathion peroxide (GSH-Px) and malon dialdehyde (MDA) in the tumor and border zone were compared with those in the non-tumor region and control normal tissue. Activities of SOD and catalase in the tumor and border zone were significantly lowered than those in non-tumor region and normal tissue. GSH-Px levels were significantly higher in the tumor than those in the non-tumor region and normal tissue. MDA levels also tended to be high in the tumor. These results suggest that the development of cancer in pancreatic tissue is related to a reduction of SOD and catalase. GSH-Px and MDA are suggested to be involved in the reactions of free radicals.