Palatine mucosa of aging and experimentally induced diabetic aging rabbits: light-microscopic, scanning electron microscopic and transmission electron microscopic qualitative study.

BACKGROUND: Data associating palatine mucosa, microvascular architecture, aging and diabetes mellitus are few, so the aim of the present study was to examine these conditions structurally and ultrastructurally. METHODS: We used 18 female rabbits, aged about 2 years at the beginning of the experiment, distributed into 2 groups: aging diabetic and aging animals, prepared by three different methodologies: light microscopy, scanning electron microscopy and transmission electron microscopy. The samples were stained with hematoxylin-eosin for light microscopy, and for scanning electron microscopy, we used Mercox Cl-2B vascular corrosion casts. For transmission electron microscopy, the specimens were fixed and embedded in Epon 812 resin. RESULTS: Under light microscopy, we noted small amounts of underdeveloped connective papillae and significant flattened areas through the epithelium-connective tissue interface in the aging diabetic group. Larger blood vessels were deeply located in the palatine mucosa, branching off in the direction of the epithelium-connective tissue interface. Capillaries followed the interface contour. In both groups, vascular corrosion casts revealed capillaries sprouting out in disorganized rows but parallel between themselves. 'Hair-pin' capillary loops and convoluted capillary loops were noted. CONCLUSION: The aging diabetic group showed rarefying microvasculature areas with complex tortuous capillary loops. Transmission electron microscopy results showed that the aging diabetic group presented small cytoplasmatic projections directed to the vessel lumen and micropinocytic vesicle, i.e. caveolas. Epithelium-connective tissue interface, connective papillae, microangioarchitecture, and information about endothelial cells alterations were observed in the aging diabetic and aging animals.

Angioarchitectural characteristics of the anterodorsal surface of aging and young rabbit tongue: scanning electron microscopy study.

The three-dimensional angioarchitecture of young and aging rabbit tongues were studied using a vascular corrosion cast method. The vascular network of different lingual papillae were observed by scanning electron microscope (SEM). Young animals showed filiform papillae distributed all over considered area, with fungiform ones among them. In comparison to developed specimens, young rabbits demonstrated dense and higher organization of microvascular network.