RETURNYonago Acta medica 1992;35:183–191
Capillary Network beneath the Epithelium of the Rat Urinary BladderScanning Electron Microscopic Study Using Alkali Digestion and Vascular Corrosion Casting
Shu-Yong Zhang*, Akira Mitsushima, Takao Inoué and Akihiro Iino
Department of Anatomy, Faculty of Medicine, Tottori University, Yonago 683, Japan
The NaOH digestion method combined with vascular corrosion casting was applied for observation of a capillary network beneath the urinary bladder epithelium by scanning electron microscopy. The rat bladders perfused with casting resin were fixed with 2.5% glutaraldehyde followed by digestion with 6 N NaOH for 10 min at 60°C. Since the epithelium was detached during the digestion, the subepithelial capillaries were clearly demonstrated together with cellular components such as pericytes and fibroblasts. After photography, the specimens were corroded and the corresponding capillaries were observed again. The subepithelial capillaries laid on a sheet of fibroblasts and formed a regular two-dimensional network over the entire mucosa of the bladder. The capillaries often had lateral buddings of newly developing capillaries. Although it was uncertain from their outer surface whether they had open cavities or not, the observations of the vascular casts were useful to study the inner aspect of the capillaries. Furthermore, the vascular casting was effective to study the relationship between the subepithelial capillaries and underlying vessels.
Key words: NaOH digestion; rat; scanning electron microscopy; subepithelial capillary; urinary bladder; vascular corrosion casting