Three-dimensional Structure of Dog Sertoli Cells: A Computer-Aided Reconstruction from Serial Semi-Thin Sections

Abstract

Vascular architecture in the periodontal ligament of hamster incisors was investigated by use of vascular casts under a scanning electron microscope (SEM). In addition to ordinary nutrient blood vessels, anastomosing vessels of large caliber developed, sur-rounding the incisor. From their characteristic con-figuration, these vessels were regarded as sinusoids. The plexus of sinusoidal vessels was connected with capillaries in the papillary layer of the enamel organ at the labial periodontal ligament, and with veins pene-trating into the alveolar bone on the lingual side. Transmission electron microscopic (TEM) observation showed that the sinusoidal wall was composed of only a thin layer of endothelial cells, lacking a smooth muscu-lar element, and surrounded by densely arranged colla-gen fibers. Although the frequent association of Ruffini-type nerve endings with siunsoidal vessels was noted, neither direct contact nor specialized structures be-tween these was recognizable. A possible function of the periodontal sinusoids is discussed on the basis of their distribution and ultrastructural evidence. © 1993, International Society of Histology and Cytology. All rights reserved.