Secretion by striated ducts of mammalian major salivary glands: Review from an ultrastructural, functional, and evolutionary perspective
Article first published online: 7 AUG 2001
Copyright © 2001 Wiley-Liss, Inc.
The Anatomical Record
Volume 264, Issue 2, pages 121–145, 1 October 2001
How to Cite
Tandler, B., Gresik, E. W., Nagato, T. and Phillips, C. J. (2001), Secretion by striated ducts of mammalian major salivary glands: Review from an ultrastructural, functional, and evolutionary perspective. Anat. Rec., 264: 121–145. doi: 10.1002/ar.1108
- Issue published online: 7 AUG 2001
- Article first published online: 7 AUG 2001
- Manuscript Accepted: 12 MAR 2001
- Manuscript Received: 11 OCT 2000
- National Institute of Dental Research
- Hofstra University
- Texas Tech University
- Illinois State University Departments of Biological Sciences.
- parotid gland;
- submandibular gland;
- secretory granules;
In addition to their role in electrolyte homeostasis, striated ducts (SDs) in the major salivary glands of many mammalian species engage in secretion of organic products. This phenomenon usually is manifested as the presence of small serous-like secretory granules in the apical cytoplasm of SD cells. The composition of these granules is largely unknown, except in the case of the cat and rat submandibular gland, where the granules have unequivocally been shown to contain kallikrein. In some species, the apical cytoplasm of SD cells contains variable numbers of vesicles, both spherical and elongated, that vary in appearance from ‘empty’ to moderately dense. In the rat parotid gland, lucent vesicles transport glycoproteins to the luminal surface where they are incorporated into the apical plasmalemma and the glycocalyx. There is a strong possibility that in various species some of these vesicles are involved in transcytosis of antibodies to the saliva from their source (plasma cells) in the surrounding connective tissue. In addition, vesicles may engage in transfer of growth factors from the saliva to the interstitium. In a few species, conventional SDs have been replaced by ducts that are wholly given over to secretion, i.e., they entirely lack basal striations; although such ducts occupy the histological position of conventional SDs, it is not clear whether they represent a new type of duct or merely are modifications of SDs. Broad-based comparisons of ultrastructural and other data about SDs offer some insight into evolutionary history of salivary glands and their role in the adaptive radiation of mammals. Evolutionary patterns emerged when we made interspecific comparisons across mammalian orders. Among the bats, there is a clear relationship between SD secretion and general categories of diet. Anat Rec 264:121–145, 2001. © 2001 Wiley-Liss, Inc.