Ultrastructure of the agranular cells in the adenohypophysis of the South American lungfish, Lepidosiren paradoxa

✍ Scribed by Akira Chiba; Shunya Oka; Yoshiharu Honma; Mikio Ishiyama

• Book ID: 102904335
• Publisher: John Wiley and Sons
• Year: 1991
• Tongue: English
• Weight: 650 KB
• Volume: 207
• Category: Article
• ISSN: 0362-2525
• DOI: 10.1002/jmor.1052070109

✦ Synopsis

Light and electron microscopic examination demonstrated two types of non-endocrine agranular cells, cavity boundary cells and stellate cells, in the adenohypophysis of the South American lungfish, Lepidosiren paradoxa. The cavity boundary cells line the hypophyseal cleft and diverticulum and display few microvilli, occasional cilia, prominent junctional complexes, and many cytoplasmic microfilaments. The stellate cells are scattered in the glandular parenchyma and are devoid of microvilli and cilia. When adjacent, they are connected to one another by desmosomes. Pinocytotic vesicles or caveolae are frequently seen along the plasma membrane of the agranular cells adjoining the endocrine cells or abutting on the basement membrane. Possible roles of the agranular cells, physically and metabolically supportive functions, are discussed on the basis of their ultrastractural features.