Studies on the Mechanism of Hypoproteinemia in Gastric Cancer: 2. Albumin Leakage into Gastric Juice in Rats with N-Methyl- N'-Nitro-N-Nitrosoguanidine Induced Gastric Cancer

In a previous paper, we reported that the leakage of serum albumininto the gastric juice definitely increased in six out of 30patients suffering from gastric cancer and discussed the mechanismsof albumin leakage into the stomach lumen. In this study, we measured the leakage of scrum albumin intothe gastric juice of rats with gastric cancer induced by N-methyl-N'-nitro-N-nitrosoguanidine(MNNG). Nine through 12 months after the beginning of MNNG administration,several rats began to show adenocarcinoma in the glandular stomach.Albumin leakage of these rats increased notably compared tonon-tumor-developing rats. In the 15th month, all the rats wereafflicted with gastric cancer, accompanied by a high leakageof serum albumin. To study the mechanism of albumin leakage, leakage of serumalbumin into the gastric juice was measured in rats which hadundergone various treatments, such as thoracic duct ligation,subcutaneous transplantation of Yoshida sarcoma, administrationof toxohormone and experimental ulccration of the stomach. Therats which were given thoracic duct ligation or those whichwere administered toxohormone all showed mild increase in theleakage of serum albumin, and a significant increase in theleakage was detected in rats bearing subcutaneously transplantedYoshida sarcoma nine or more days after transplantation. Onthe other hand, the leakage scarcely increased in the rats withexperimental gastric ulcer. From these results, we considered that the causes of albuminleakage into the gastric juice in cases with gastric cancercan be attributed not only to the local changes of the gastricwall but also to a systemic phenomenon associated with the tumor-bearinghost. ^*This study was supported by a grant from the Ministry of Healthand Welfare.