Histochemical localization at the electron microscopic level of sulfated glycosaminoglycans in the rat gingiva

Abstract

Using the high iron diamine thiocarbohydrazide silver proteinate (HID-TCH-SP) staining technique, we investigated ultrastructural localization of sulfated glycosaminoglycans (GAGs) in the rat gingiva shortly after eruption, especially those associated with internal and external basal laminae. In the apical portion of the internal basal lamina, HID-TCH-SP stain deposits were distributed mainly in the region of the lamina lucida located between the lamina densa and the distal surface membrane of the junctional epithelium and inside the depression of the distal surface membrane adjacent to the basal lamina. Stain deposits were also detected on the surface membrane of the cytoplasmic protrusion. Interestingly, the density of HID-TCH-SP stain deposits in the internal basal lamina was highest in the apical portion of the junctional epithelium and decreased in the coronal direction, finally tending to disappear completely. On the other hand, in the external basal lamina the deposits were localized in the whole region of the basal lamina or at both sites of the lamina densa. HID-TCH-SP stain deposits were also detected external to the lamina densa in the basement membrane associated with capillaries and in the connective tissue where they were distributed in close relation to collagen fibrils. Testicular hyaluronidase digested most HID-TCH-SP stain deposits in the connective tissue, whereas those in the region of basement membranes resisted this enzymatic digestion.

The Junctional Epithelium: from Health to Disease

“…While the external basement membrane of the junctional epithelium resembles, in its structure and composition, other basement membranes that are interposed between an epithelium and a connective tissue, the internal basal lamina has distinctively different structural and molecular characteristics. It lacks most of the common basement membrane components such as collagen types IV and VII, most laminin isoforms, perlecan, and a lamina fibroreticularis (Salonen and Santti, 1985;Kogaya et al, 1989;Sawada et al, 1990;Salonen et al, 1991;Oyarzun-Droguett, 1992;Hormia et al, 2001). Laminin-5, however, appears to be expressed in the internal basal lamina but not in the external basement membrane of the junctional epithelium, at least in rats (Oksonen et al, 2001).…”

The epithelial attachment and the dental junctional epithelium: Ultrastructural features in porcine molars

“…Attempts to understand the determinants and mechanism of this attachment have concentrated on analysis of components in situ in normal tissue and during regeneration of experimentally-modified or detached junctional epithelium. Studies of the composition of the junctional epithelium have identified in the epithelial attachment type VIII collagen (Salonen et al, 19911, integrins (Hormia et al, 1992), sulfated glycosaminoglycans (Kogaya et al, 1989), epidermal growth factor (Tajima et al, 19921, and proteoglycans (Oyarzun-Droguett, 1992). Type IV collagen and laminin are found in the external basement membrane (Hormia et Fig.…”

High resolution and image processing of otoconia matrix

“…The very first appearance of otoconia may be initially independent of calcium integration into those fibrils (Kogaya et al, 1989). The initial stage(s) and duration of otoconia formation may be demarcated by organic fibrils seen first attached to the stereocilia (Cohen and Fermin, 1985).…”

“…Since glycosaminoglycans are intimately associated with both processes of cartilage mineralization (Buck-Walter et al, 1987) and teeth and bone calcification (Kogaya et al, 1989;Takagi et al, 1986;Takagi et al, 19911, they could also play an important role in the mineralization of otoconia. Glycosaminoglycans aid in crystallization of collagen gels Hunter, 1987).…”