Light and Electron Microscopic Studies of the Rat Hyalocyte after Perfusion Fixation

Abstract

The characteristic morphology of a not intentionally stimulated hyalocyte is described, using TEM and perfusion fixation. The best results were obtained by retrograde perfusion via the abdominal aorta with a glutaraldehyde- and formaldehyde-containing fixative. The cells, situated in the cortical area of the vitreous body, show mostly an indented nucleus, primary and secondary lysosomes, mitochondria, cisterna, clusters of free ribosomes and a Golgi apparatus. Bristle-coated micropinocytotic vesicles can also be distinguished and in some cells a centriole is visible. Sometimes the cells show many cytoplasmic protuberances. Morphologically the majority of those cells can be considered as resting macrophages.

Role of TGF-β in proliferative vitreoretinal diseases and ROCK as a therapeutic target

“…These cells organize into the proliferative membrane (3,4). Hyalocytes are found in the cortical vitreous in the vicinity of the inner retinal surface (5). Morphological studies suggest that hyalocytes may belong to the monocyte/ macrophage lineage (6,7).…”

Transforming Growth Factor-β2 and Connective Tissue Growth Factor in Proliferative Vitreoretinal Diseases

“…Hyalocytes are the cells located in the cortical vitreous abutting the inner surface of the retina (21). Morphological studies have demonstrated that hyalocytes, which possess lysosome-like granules, mitochondria, and micropinocytotic vesicles in their cytoplasm, belong to the monocyte/ macrophage lineage (22)(23)(24).…”

Functional Properties of Hyalocytes under PDGF-Rich Conditions

“…2 It is reported that the hyalocytes mainly subsist in the vitreous cortex, vitreous base, and posterior chamber. 3,4 Histologically, the hyalocytes have characteristics similar to those of macrophages. They possess lysosomes, mitochondria, ribosomes, and micropinocytotic vesicles, 3 and express leukocyte-associated antigens CD45, CD11a, CD64, and S-100 and major histocompatibility complex class I and II, but do not express CD68, CD11b, CD14, glial fibrillary acidic protein (GFAP), and cytokeratin.…”

“…3,4 Histologically, the hyalocytes have characteristics similar to those of macrophages. They possess lysosomes, mitochondria, ribosomes, and micropinocytotic vesicles, 3 and express leukocyte-associated antigens CD45, CD11a, CD64, and S-100 and major histocompatibility complex class I and II, but do not express CD68, CD11b, CD14, glial fibrillary acidic protein (GFAP), and cytokeratin. 5 Although most of the facilities and roles of hyalocytes remain unclear, the hyalocytes are thought to be one of the macrophage lineage and are likely to be broadly associated with physiological and pathologic conditions, including the maintenance of the vitreous as avascular and transparent tissue.…”