Vitamin A-Storing Stellate Cells in the Human Newborn Vocal Fold

Abstract

Vocal fold stellate cells (VFSCs) in the newborn vocal fold were examined and compared with VFSCs in the adult vocal fold. Light and electron microscopic investigation of VFSCs was carried out on 5 human newborn larynges. The VFSCs were distributed in human newborn maculae flavae. They were stellate or oval in shape, and possessed cytoplasmic processes. The VFSCs in some cells formed a gap junction with each other. A few lipid droplets were present in the cytoplasm, but they were much fewer than those of an adult. The nucleus-cytoplasm ratio was high, and the intracellular organelles were not very well developed. Free ribosomes were well developed in the cytoplasm. The VFSCs in some cells showed strong cytoplasm staining with periodic acid-Schiff stain and type III collagen. There were vesicles along the periphery of the cytoplasm of the VFSCs, and newly released amorphous materials were seen, but fewer were observed on the cell surface. The newborn VFSCs had started to synthesize extracellular matrices such as collagenous fibers, reticular fibers, elastic fibers, and glycosaminoglycan. The VFSCs in the newborn maculae flavae were immature, but had already started the synthesis of extracellular matrices essential for the viscoelastic properties of the vocal fold mucosa.