Cytochemical identification of lysosomal system of the rat junctional epithelium

Abstract

Structures taking part in the lysosomal system of rat junctional epithelium (JE) were evaluated by means of ultrastructural enzyme cytochemistry. Acid phosphatase (AcPase) and trimetaphosphatase (TMPase), both the representative lysosomal marker enzymes, were frequently detected in dense bodies which contained the homogeneous matrix and showed pleomorphic appearance. These activities were also often localized to the phagosomes with heterogeneous contents, the reaction of TMPase being much more intense than that of AcPase. Cisternal structures, most probably corresponding to GERL, also displayed AcPase activity and exhibited the close morphologic relationships with lysosomal structures. On the other hand, the localization of thiamine pyrophosphatase activity was almost limited to the innermost cisterna of the Golgi complex. Neither AcPase nor TMPase activity could be detected in the cytoplasmic vacuoles, which were characteristically numerous in rat JE and the multivesicular bodies. From the present findings, it is suggested that the lysosomal system in rat JE is composed of dense bodies (primary lysosomes), phagolysosomes (secondary lysosomes), and GERL and that some of those lysosomes are apparently derived from GERL. Different localization patterns of marker enzymes examined might reflect the enzymatic heterogeneity of various lysosomal elements.

Effect of colchicine on the three-dimensional organization of elongated lysosomes(Nematolysosomes) in rat pancreatic exocrine cells.

“…Recently, the presence of elongated lysosomes, termed "nematolysosomes" or "tubular lysosomes", has been increasingly known in variety cell types, such as macrophages (2, 3, 8-10, 22,23,25), hepatocytes (14), exocrine cells (4-6, [15][16][17][18], smooth muscle cells (20) and others (12,21,24). The characterization of nematolysosomes has been studied most extensively in macrophages (2, 3, 8-10, 22,23,25), although the physiological role of the lysosomes in other cell types is still unknown.…”

Penetration and Uptake of Colloidal Gold‐Labeled Concanavalin A in The Junctional Epithelium of The Rat

“…The junctional epithelial cells took up many gold particles into their lysosomal and vacuolar structures (arrows) (magnification x 33,000). 11. Electron micrograph ofthe junctional epithelium after topical application of CG-Con A for two hours.…”

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

“…Asterisks (c) throughout the length of this epithelium, but are more numerous at the coronal end near the base of the gingival sulcus. All cells of the junctional epithelium are remarkably similar in organelles and cytoarchitecture (Schroeder, 1986); however, for epithelial cells, there are relatively few cytoplasmic filaments and intercellular attachments (Yamasaki et al, 1985). Together, they form a unique non-keratinizing stratified epithelium that shows an unusual expression of the keratins found in other stratified and simple epithelia (Mackenzie et al, 1991).…”