[Study of mechanisms of increasing serum RNase]

In 1976 Reddi et al. reported increase of serum Ribonuclease (RNase) in pancreatic cancer patients. In this study, the increase in serum RNase activity was observed in patients with pancreatic cancer, coincided with the report by Reddi et al. The increase was also observed in patients with advanced gastric cancer. Especially, in patients with cancer invasion into pancreas, high value was obtained. Patients with other cancers showed the elevation of RNase activities. Thus, the elevation of serum RNase level is not specific only to patients with pancreatic cancer. An selectric focusing test showed no distinguishable difference in patients with pancreatic cancer and healthy persons. In mice with transplanted tumor of pancreas, serum RNase increased. Simultaneously, histological dilatation of pancreatic ducts and destruction of acinus were observed. When pancreas was occupied by tumor, serum RNase was decreased. These results suggest that RNase is not produced by cancer cell but is released from pancreas itself.