[Induction of dietetic diabetes in Microtus arvalis Pallas and its developmental mechanism]

Abstract

In Microtus arvalis Pallas, new born voles were fostered to ICR mice and supplied with pellets for mice after weaning. A high concentration of glycosuria was shown in about 50% of the voles and continued for over ten weeks. Concentrations of blood glucose and plasma FFA iun glycosuric voles were three or four times as high as those in normal controls. The fermentation ability and pH lowered in the esophageal sac, and comparatively large amount of starch existed in the pyloric stomach of the glycosuric voles. This demonstrated that the dietary starch were tolerably transported to the pyloric stomach without being fermented in the esophageal sac. Glycosuria was also induced in about 50% of the voles supplied with an acidified water (0.02 N HCl, pH 1.7), and the glycosuric voles showed a low pH (1.4-4.2) and lowering of the fermentative ability in esophageal sac. Such an abnormal fermented conditions in the esophageal sac is considered to induce glycosuria in the voles. Glucose tolerance in the diabetic voles which were supplied with pellets for mice lowered considerably with the progress of the disease. On the other hand, plasma insulin levels in the slight diabetic cases rose to eight times as high as normal level, but they lowered considerably with the progress. In the serious cases, the voles fell into complete insulin deficiency. From the above results, the herbivorous Microtus species was considered to be useful as an "animal model" of the dietetic diabetes.