Endocytosis of native and cationized ferritin by intralobular duct cells of the rat parotid gland

The GTP-binding protein G(o) was localized immunohistochemically in the rat parotid gland and in other exocrine glands with specific G(o) antibodies. Immunohistochemical studies revealed that affinity-purified G(o alpha) polyclonal antibody (GO/85) immunoreacted primarily with duct cells of the rat parotid gland; immunoreactivity was also noted in duct cells of the rat submandibular, mouse parotid, and mouse submandibular glands. Light labeling of rat parotid and submandibular gland acinar cells was also noted. G(o alpha) antiserum (9072) differing in specificity for epitopes within G(o alpha) produced similar results. This antiserum also immunoreacted with rat submandibular duct cell secretory granule membranes. In contrast, in rat and mouse pancreas G(o alpha) antibodies immunoreacted primarily with islet cells. Duct cells were negative but there was light labeling of rat pancreatic acinar cells. The apparent duct specificity of G(o alpha) staining was further verified by demonstrating that G(o alpha) antibodies immunoreacted with HSG-PA cells, a human transformed salivary duct cell line. Specificity in immunohistochemical labeling of HSG-PA cells was confirmed by Western blot analysis. The results demonstrate that G(o) appears to be selectively expressed in the duct cells of rat parotid gland and other salivary glands. The selective enrichment of G(o) in duct cells suggests that this G-protein plays an important role in duct cell physiology.

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Intercalated duct cells in the rat parotid gland may behave as tissue stem cells

Anatomical Science International ◽

10.1007/s12565-009-0019-0 ◽

2009 ◽

Vol 84 (3) ◽

pp. 148-154 ◽

Cited By ~ 8

Author(s):

Osamu Katsumata ◽

Yu-Ichi Sato ◽

Yasuhiro Sakai ◽

Shohei Yamashina

Keyword(s):

Stem Cells ◽

Parotid Gland ◽

Duct Cells ◽

Rat Parotid Gland ◽

Rat Parotid

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Mitosis and Hypertrophy of Intercalated Duct Cells and Endothelial Cells in the Isoproterenol-treated Rat Parotid Gland

Journal of Dental Research ◽

10.1177/00220345850640080201 ◽

1985 ◽

Vol 64 (8) ◽

pp. 1031-1038 ◽

Cited By ~ 19

Author(s):

A.R. Hand ◽

B. Ho

Keyword(s):

Endothelial Cells ◽

Salivary Gland ◽

Endothelial Cell ◽

Parotid Gland ◽

Chronic Treatment ◽

Cytoplasmic Organelles ◽

Duct Cells ◽

Rat Parotid Gland ◽

Pinocytotic Vesicles ◽

Rat Parotid

Chronic treatment of rats with isoproterenol (IPR) induces mitosis and differentiation of intercalated duct cells, and mitosis and hypertrophy of endothelial cells of the microvasculature in the parotid gland. Mitoses occurred in duct cells situated at or near the acinar-intercalated duct junction, and were most numerous after six IPR injections. These cells increased in size, contained numerous electronlucent granules, and were incorporated into the hypertrophic acini. The granules contained branching filamentous or finely reticulated material, and did not react with histochemical stains for carbohydrate. Capillary and venule endothelial cell mitoses were frequently seen after four to six IPR injections. The endothelial cells increased in thickness, contained abundant cytoplasmic organelles, lacked fenestrations, and had few pinocytotic vesicles. These results demonstrate the extensive nature of the response to chronic IPR treatment, and are consistent with the concept that the intercalated ducts have an important role in salivary gland physiology.

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Quantitative immunoelectron microscopic localization of (Na+,K+)ATPase in rat parotid gland.

Journal of Histochemistry & Cytochemistry ◽

10.1177/35.8.3036942 ◽

1987 ◽

Vol 35 (8) ◽

pp. 871-879 ◽

Cited By ~ 11

Author(s):

T Iwano ◽

M Akayama ◽

A Yamamoto ◽

K Omori ◽

T Kumazawa ◽

...

Keyword(s):

Parotid Gland ◽

Plasma Membranes ◽

Basolateral Membrane ◽

Protein A ◽

Acinar Cells ◽

Gold Particles ◽

Duct Cells ◽

Rat Parotid Gland ◽

Basal Plasma ◽

Rat Parotid

Distribution of (Na+,K+)ATPase on the cell membranes of acinar and duct cells of rat parotid gland was investigated quantitatively by immunoelectron microscopy using the post-embedding protein A-gold technique. In acinar cells, ATPase was localized predominantly on the basolateral plasma membranes. A small but significant amount of (Na+,K+)ATPase was, however, detected on the luminal plasma membranes, especially on the microvillar region of the acinar cells; the surface density on the luminal membrane was approximately one third of that on the basolateral membranes. In duct cells, many gold particles were found on the basolateral membrane, especially along the basal infoldings of the plasma membranes, whereas no significant gold particles were found on the luminal plasma membranes, suggesting unilateral distribution of ATPase in duct cells. We suggest that in acinar cells sodium ion is not only transported paracellularly but is also actively transported intracellularly into the luminal space by the (Na+,K+)ATPase located on the luminal plasma membranes, and that water is passively transported to the luminal space to form a plasma-like isotonic primary saliva, while in the duct cells the same ion is selectively re-absorbed intracellularly by (Na+,K+)ATPase found in abundance along the many infoldings of the basal plasma membranes, thus producing the hypotonic saliva.

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