Ultrastructural study of capillary and myocytic changes in the masseter and heart of KK-Ay mice.
We studied the capillaries and myocytes of masseter and cardiac muscles of diabetic KK-Ay mice, using light microscopy, transmission electron microscopy and scanning electron microscopy. The following changes were observed for diabetic masseters: capillary tortuosity, diversity of capillary caliber, endothelial cell swelling accompanied by luminal narrowing, widening of the pericapillary space and pericapillary fibrosis, and subsarcolemmal accumulation of myocytic mitochondria in areas adjacent to capillaries. In addition, attenuated capillary segments were largely covered by pericytes with profuse processes. In contrast, cardiac muscles of KK-Ay mice exhibited subsarcolemmal accumulation of myocytic mitochondria in areas contiguous to capillaries, and degenerative changes of myocytes such as disarrangement of myofilaments, disappearance of Z-bands and clustering of lipid-like vacuoles, although conspicuous changes of capillaries were not noted. Microvascular and myocytic changes described above may suggest the presence of microangiopathy and myopathy in the masseter and heart of KK-Ay mice.
Takeshita
M
M
Department of Anatomy, Oita Medical University, Japan.
Ina
K
K
Kitamura
H
H
Shimada
T
T
Nakamura
M
M
D000818:Animals; D001485:Basement Membrane / Q000648:ultrastructure; D001786:Blood Glucose / Q000032:analysis; D001835:Body Weight; D002196:Capillaries / Q000648:ultrastructure*; D002462:Cell Membrane / Q000648:ultrastructure; D003331:Coronary Vessels / Q000648:ultrastructure*; D003921:Diabetes Mellitus, Experimental / Q000473:pathology; D004727:Endothelium / Q000648:ultrastructure; D050356:Lipid Metabolism; D008297:Male; D008406:Masseter Muscle / Q000098:blood supply* / Q000648:ultrastructure*; D051379:Mice; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D008928:Mitochondria / Q000648:ultrastructure; D009130:Muscle, Smooth / Q000648:ultrastructure*; D014617:Vacuoles / Q000648:ultrastructure
D001786:Blood Glucose