elastin and thiocarbohydrazide

In the ventral aorta of lamprey, microfibrils are major components of the extracellular matrix. With special reference to these microfibrils, we have cytochemically examined the lamprey ventral aorta, utilizing the tannic acid (pH 7.0)-uranyl acetate (TA-UA) method, elastase en bloc digestion, Thiéry's periodic acid-thiocarbohydrazide-silver proteinate (PA-TCH-SP) method, and ferritin- or horseradish peroxidase-labeled concanavalin A (Con A) methods. The lamprey microfibrils were strongly stained with PA-TCH-SP and both Con A methods, but did not show TA-UA staining nor elastase sensitivity. These cytochemical properties of lamprey microfibrils are identical with those of mammalian elastin-associated microfibrils. On the other hand, in spite of extensive examination, TA-UA positive and elastase-sensitive extracellular components were not found, so that lamprey ventral aorta does not appear to contain elastin. These results indicate that lamprey aortic connective tissue contains microfibrils as elastic components, but deposition of amorphous elastin does not occur.

Topics: Actin Cytoskeleton; Animals; Aorta; Carbohydrate Metabolism; Concanavalin A; Cytoskeleton; Elastin; Ferritins; Fishes; Glycols; Histocytochemistry; Horseradish Peroxidase; Hydrazines; Lampreys; Microscopy, Electron; Periodic Acid; Silver Proteins

Fullmer's oxytalan fibers are special connective tissue fibers in periodontal ligaments and some non-dental sites of certain animal species, and, ultrastructurally appear to resemble microfibrils related to elastogenesis. The present study has ultrastructurally examined the applicability of Thiéry's periodic acid-thiocarbohydrazide-silver proteinate (PA-TCH-SP) method for vicinal glycol-containing complex carbohydrates to the study of oxytalan fibers in rat periodontal ligaments and microfibrils of the tunica adventitia in the rat aorta, where microfibrils are often associated with amorphous elastin and are thought to be oxytalan fibers. In the periodontal ligaments, the PA-TCH-SP method weakly to moderately stained collagen fibrils, moderately stained thin fibrils composing the oxytalan fibers, and intensely stained cytoplasmic granules of fibroblasts. In the aortic adventitia, the PA-TCH-SP method moderately stained collagen fibrils. Heavier staining was observed in microfibrils, whereas the amorphous elastin lacked staining. The most intense staining was seen in cytoplasmic granules and glycogen of mural cells. These studies demonstrate that oxytalan fibers in the periodontal ligament of rats and microfibrils in the aorta of rats contain vicinal glycol-containing glycoproteins and the PA-TCH-SP method is a useful tool in ultrastructural studies of oxytalan fibers and microfibrils of rats.

Topics: Animals; Aorta; Collagen; Connective Tissue; Cytoplasmic Granules; Elastic Tissue; Elastin; Fibroblasts; Glycols; Hexoses; Hydrazines; Indicators and Reagents; Periodic Acid; Periodontal Ligament; Rats; Rats, Inbred Strains; Silver Proteins; Staining and Labeling