Abstract
KK mice known to be spontaneously diabetic animals, develop various morphologic changes, but little work has been done to study relationships between those changes and the diabetic state. In this study, an attempt to control the diabetic state of KK mice was made by diet limitation, and morphologic changes in the controlled KK mice were compared with those in diabetic animals.
Male mice of the KK strain were divided into two groups: one group was given a daily amount of food limited to 3-4.5 g/body so as to weigh 30-35 g (controlled group), and the other was permitted free access to food (non-controlled group). They all were examined for diabetic symptoms from 4 to 10-16 months of age and observed histologically for changes in the organs.
In the controlled group, the diet limitation successfully restored blood glucose and glucose tolerance to normal and abolished glycosuria. When examined histologically, such changes characteristic to the KK strain as increased cells in the islets of Langerhans, an irregularly thickened glomerular basement membrane and increased mesangial matrix in renal glomeruli were apparently improved; improvement of the former change in particular had a close relationship with the period of recovery from the diabetic state. On the one hand, these controlled animals, like the non-controlled animals, showed calcification mainly in small and medium-sized arteries in the heart, lung, and kidney.
These findings suggest that progress of the changes in the islets of Langerhans and the renal glomeruli is related to the diabetic state of KK mice and that calcification noted in the heart, lung, and kidney may be a change attributable to some other factor.
