title: Differential distribution and ultrastructural staining of oxytalan and elastic fibers in the periodontal ligament of Alligator mississippiensis.
abstract: We have investigated ultrastructural cytochemical properties of elastic elements in Alligator periodontal ligaments decalcified with EDTA and stained with 1) the tannic acid-uranyl acetate (TA-UA) method for elastin in combination with elastase digestion; 2) the high iron diamine-thiocarbohydrazide-silver proteinate (HID-TCH-SP) method with prior treatment of specimens with either monopersulphate or cupric-sulphite reagent for the localization of disulphide- and/or sulphydryl-containing material (i.e., oxytalan fibers); and 3) HID-TCH-SP alone for sulphated complex carbohydrates. Many microfibrils accumulated to form either large or small bundles. Large bundles having a diameter of 2.50 +/- 1.10 microns (mean +/- SD; n = 50) each showed an apico-occlusal distribution, although small bundles measuring 0.63 +/- 0.13 microns (mean +/- SD; n = 50) in diameter each were exclusively localized in interstitial areas rich in vessels and nerves. The former bundles always lacked TA-UA reactivity and represented oxytalan fibers; the latter bundles frequently contained TA-UA-reactive elastase digestible components and were similar in appearance to immature elastic fibers or elaunin fibers. HID-TCH-SP after oxidation strongly stained both the oxytalan and elastic fiber microfibrils but stained the amorphous elastin very weakly or not all. In nonoxidized specimens, there was no definite HID-TCH-SP staining of microfibrils and the amorphous elastin, although adjacent matrix proteoglycans stained consistently. These results indicate that although there is a marked difference in the distribution and size of oxytalan and elastic fibers in Alligator periodontal ligaments, their associated microfibrils lack stainable sulphate groups but are enriched with disulphide and/or sulphydryl groups, as has been described in mammals.
authors: Department of Anatomy, Nihon University School of Dentistry, Tokyo, Japan.
authors: M
authors: M
authors: Takagi
authors: T
authors: T
authors: Kazama
authors: K
authors: K
authors: Shimada
authors: Y
authors: Y
authors: Hosokawa
authors: H
authors: H
authors: Hishikawa
mesh_terms: D000489:Alligators and Crocodiles / Q000033:anatomy & histology / Q000378:metabolism*; D000818:Animals; D003285:Contractile Proteins / Q000378:metabolism*; D004547:Elastic Tissue / Q000378:metabolism* / Q000648:ultrastructure; D004549:Elastin / Q000378:metabolism; D016326:Extracellular Matrix Proteins; D006651:Histocytochemistry; D008854:Microscopy, Electron; D010513:Periodontal Ligament / Q000378:metabolism* / Q000648:ultrastructure; D000072260:RNA Splicing Factors; D012104:Reptiles / Q000378:metabolism*; D013194:Staining and Labeling / Q000379:methods
chemical_list: D003285:Contractile Proteins; D016326:Extracellular Matrix Proteins; D000072260:RNA Splicing Factors; C016598:microfibrillar protein; D004549:Elastin