THE ENDOCRINE PANCREAS OF SPONTANEOUSLY DIABETIC DB DB MICE - MICROANGIOPATHY AS REVEALED BY TRANSMISSION ELECTRON-MICROSCOPY/

Abnormalities in ultrastructures of islet capillaries were detected in db/db mice, with the visual inspection and morphometry of electron mi crographs. The observed changes are: (1) capillary scarcity; (2) incre ase in the mean and diversity of capillary size; (3) pericapillary ede ma and fibrosis; (4) hypertrophy of the pericyte and abundance therein of actin-like microfilaments; and (5) luminal irregularity. Changes ( 2), (3) and (4) are conceived to indicate hyperperfusion, capillary hy pertension and secondary vascular response. In particular. such pericy te changes were found to be shared by other organs whose capillaries a re susceptible to diabetic complications.