scholarly journals MORPHOLOGIC AND CYTOCHEMICAL IDENTIFICATION OF PEROXISOMES IN THE RAT PAROTID AND OTHER EXOCRINE GLANDS

1973 ◽  
Vol 21 (2) ◽  
pp. 131-141 ◽  
Author(s):  
ARTHUR R. HAND
Keyword(s):  
Endoplasmic Reticulum ◽  
Parotid Gland ◽  
Parenchymal Cell ◽  
Cell Types ◽  
Exocrine Glands ◽  
Widespread Occurrence ◽  
Duct Cells ◽  
Low Concentrations ◽  
Endogenous Peroxidase ◽  
Rat Parotid

Peroxisomes were identified in all three parenchymal cell types of the rat parotid gland. They averaged 0.33 µ in diameter in the acinar and intercalated duct cells, and 0.22 µ in the striated duct cells. They were closely related to the endoplasmic reticulum, occasionally in continuity with smooth surfaced cisternae and often embraced by ribosome-free portions of endoplasmic reticulum which paralleled their membrane. Glutaraldehyde fixation inhibited the endogenous peroxidase of the parotid gland and allowed visualization of the peroxisomes following incubation in alkaline diaminobenzidine medium. Peroxisomal staining was unaffected by varying H2O2 concentrations or low concentrations of KCN, but was prevented by aminotriazole and dichlorophenolindophenol. Examination of other exocrine glands after incubation in diaminobenzidine medium revealed the presence of peroxisomes in the pancreas, submandibular, lacrimal, nasal mucosal and von Ebner's glands. These studies indicate that peroxisomes are of widespread occurrence in exocrine tissues of the rat.

scholarly journals Localization of the G-protein G(o) in exocrine glands.

1994 ◽  
Vol 42 (1) ◽  
pp. 41-47 ◽  
Author(s):  
E L Watson ◽  
C Oliver ◽  
N D'Silva ◽  
C M Belton
Keyword(s):  
Parotid Gland ◽  
G Protein ◽  
Acinar Cells ◽  
Duct Cell ◽  
Protein G ◽  
Cell Physiology ◽  
Exocrine Glands ◽  
Duct Cells ◽  
Rat Parotid Gland ◽  
Rat Parotid

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.

Functional Organization of the Endoplasmic Reticulum Dictates the Susceptibility of Target Cells to Arsenite-Induced Mitochondrial Superoxide Formation, Mitochondrial Dysfunction and Apoptosis

2021 ◽  
Author(s):  
Andrea Guidarelli ◽  
Alessia Catalani ◽  
Ersilia Varone ◽  
Stefano Fumagalli ◽  
Ester Zito ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Mitochondrial Dysfunction ◽  
Functional Organization ◽  
Close Contact ◽  
Cell Types ◽  
Target Cells ◽  
Close Apposition ◽  
Mitochondrial Superoxide ◽  
Low Concentrations ◽  
Absolute Requirement

Abstract Arsenite induces many critical effects associated with the formation of reactive oxygen species (ROS) through different mechanisms. We focused on the Ca2+-dependent mitochondrial superoxide (mitoO2-.) formation and addressed questions on the effects of low concentrations of arsenite on the mobilization of the cation from the endoplasmic reticulum and the resulting mitochondrial accumulation. Using various differentiated and undifferentiated cell types uniquely expressing the inositol-1, 4, 5-triphosphate receptor (IP3R), or both the IP3R and the ryanodine receptor (RyR), we determined that expression of this second Ca2+ channel is an absolute requirement for mitoO2-. formation and for the ensuing mitochondrial dysfunction and downstream apoptosis. In arsenite-treated cells, RyR was recruited after IP3R stimulation and agonist studies indicated that in these cells RyR is in close apposition with mitochondria. It was also interesting to observe that arsenite fails to promote mitochondrial Ca2+ accumulation, mitoO2-. formation, mitochondrial toxicity in RyR-devoid cells, in which the IP3R is in close contact with the mitochondria. We therefore conclude that low dose arsenite-induced mitoO2- formation and the resulting mitochondrial dysfunction and toxicity, are prerequisite of cell types expressing the RyR in close apposition with mitochondria.

scholarly journals Parotid microsomal Ca2+ transport. Subcellular localization and characterization

1982 ◽  
Vol 208 (3) ◽  
pp. 789-794 ◽  
Author(s):  
P Kanagasuntheram ◽  
T S Teo
Keyword(s):  
Endoplasmic Reticulum ◽  
Parotid Gland ◽  
Subcellular Localization ◽  
Microsomal Fraction ◽  
Narrow Range ◽  
Differential Centrifugation ◽  
Linear Rate ◽  
Rat Parotid Gland ◽  
Rat Parotid ◽  
Nadph Cytochrome C Reductase

Rat parotid gland homogenates were fractionated into mitochondrial, heavy microsomal and light microsomal fractions by differential centrifugation. ATP-dependent 45Ca2+ uptake by the subcellular fractions paralleled the distribution of NADPH-cytochrome c reductase, an enzyme associated with the endoplasmic reticulum. The highest rate of Ca2+ uptake was found in the heavy microsomal fraction. Ca2+ uptake by this fraction was dependent on the presence of ATP and was sustained at a linear rate by 5 mM-oxalate. Inhibitors of mitochondrial Ca2+ transport had no effect on the rate of Ca2+ uptake. Na+ and K+ stimulated Ca2+ uptake. At optimal concentrations. Na+ stimulated Ca2+ uptake by 120% and K+ stimulated Ca2+ uptake by 260%. Decreasing the pH from 7.4 to 6.8 had little effect on Ca2+ uptake. The Km for Ca2+ uptake was 3.7 microM free Ca2+ and 0.19 mM-ATP. Vanadate inhibited Ca2+ uptake; 60 microM-vanadate inhibited the rate of Ca2+ accumulation by 50%. It is concluded that the ATP-dependent Ca2+ transport system is located on the endoplasmic reticulum and may play a role in maintaining intracellular levels of free Ca2+ within a narrow range of concentration.

Tracer uptake by duct cells of rat parotid gland

1985 ◽  
Vol 17 (2) ◽  
pp. 162
Author(s):  
R. Coleman ◽  
A.R. Hand
Keyword(s):  
Parotid Gland ◽  
Tracer Uptake ◽  
Duct Cells ◽  
Rat Parotid Gland ◽  
Rat Parotid

The synthesis of α-amylase by rough and in vitro reconstituted rough endoplasmic reticulum derived from rat parotid gland

1976 ◽  
Vol 2 (6) ◽  
pp. 455-463
Author(s):  
Bernard Cwikel ◽  
Rachel Avner ◽  
Henryk H. Czosnek ◽  
Abraham A. Hochberg ◽  
Nathan de Groot
Keyword(s):  
Endoplasmic Reticulum ◽  
Parotid Gland ◽  
Rough Endoplasmic Reticulum ◽  
Rat Parotid Gland ◽  
Rat Parotid

scholarly journals Anion secretory functions of acinar and intralobular duct cells in the rat parotid gland

2009 ◽  
Vol 56 (Supplement) ◽  
pp. 299-300
Author(s):  
Chikara Hirono ◽  
Makoto Sugita ◽  
Yoshiko Iwasa ◽  
Yoshiki Shiba
Keyword(s):  
Parotid Gland ◽  
Duct Cells ◽  
Rat Parotid Gland ◽  
Rat Parotid

scholarly journals Identification and Localization of G Proteins in Exocrine Glands

1993 ◽  
Vol 4 (3) ◽  
pp. 407-414
Author(s):  
Eileen L. Watson ◽  
Dennis Di Julio ◽  
Dolphine Oda ◽  
Kenneth T. Izutsu ◽  
Constance Oliver
Keyword(s):  
Parotid Gland ◽  
Salivary Glands ◽  
G Proteins ◽  
Acinar Cells ◽  
Pancreatic Acinar Cells ◽  
Cell Physiology ◽  
Exocrine Glands ◽  
Ductal Cells ◽  
Ductal Cell ◽  
Rat Parotid

GTP-binding proteins were identified in rat parotid acinar plasma-enriched membranes (PM) by immunoblot analysis and localized immunohistochemically in the parotid gland as well as in other exocrine glands by using affinity-purified antisera specific for alpha subunits of the G proteins. Isolated rat parotid acinar PM immunoreacted strongly to antisera directed against Gsa, Giα1/α2, Gia3, and Goa; the signal for Goa, however, was weak with crude Go antisera. Immunohistochemical studies to identify and localize Go in rat parotid tissue revealed that antisera to Goα immunoreacted with ductal cells. In addition, strong immunoreactivity to Goa antisera was noted in ductal cells of other salivary glands including rat submandibular, mouse parotid, and mouse submandibular glands. Light labeling of rat parotid and submandibular gland acinar cells was also noted. In contrast, in the rat and mouse pancreas, Go antisera immunoreacted primarily with islet cells. Ductal cells were negative, but there was light labeling of rat pancreatic acinar cells. The apparent ductal specificity of Goa staining was further verified by demonstrating that Goa antisera immunoreacted strongly with HSG-PA cells, a human transformed salivary ductal cell line. The results demonstrate that rat parotid acinar plasma membranes express a number of G proteins including Go and that Go appears to be selectively expressed in the ductal cells of rat parotid gland and other salivary glands. The selective enrichment of Go in ductal cells suggests that this G protein may play an important role in ductal cell physiology.

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