Association of gap junctions with endoplasmic reticulum in rat parotid glands

1984 ◽  
Vol 238 (3) ◽  
Author(s):  
James Dunn ◽  
J.-P. Revel
Keyword(s):  
Endoplasmic Reticulum ◽  
Gap Junctions ◽  
Parotid Glands ◽  
Rat Parotid

scholarly journals The (Ca2+ + Mg2+)-stimulated ATPase of the rat parotid endoplasmic reticulum

1986 ◽  
Vol 235 (2) ◽  
pp. 491-498 ◽  
Author(s):  
P Thiyagarajah ◽  
S C Lim
Keyword(s):  
Endoplasmic Reticulum ◽  
Cyclic Amp ◽  
Plasma Membranes ◽  
Specific Activity ◽  
Reductase Activity ◽  
Gradient Centrifugation ◽  
Fold Increase ◽  
Parotid Glands ◽  
Tissue Homogenates ◽  
Rat Parotid

A membrane fraction enriched in endoplasmic reticulum was prepared from rat parotid glands by using sucrose-gradient centrifugation. The fraction showed a 10-fold increase in specific activity of NADPH: cytochrome c reductase activity over that of tissue homogenates and minimal contamination with plasma membranes or mitochondria. The endoplasmic reticulum fraction possessed both Mg2+ -stimulated ATPase as well as Ca2+, Mg2+-ATPase [(Ca2+ + Mg2+)-stimulated ATPase]activity. The Ca2+, Mg2+-ATPase required 2-5 mM-Mg2+ for optimal activity and was stimulated by submicromolar concentrations of free Ca2+. The Km for free Ca2+ was 0.55 microM and the average Vmax. was 60 nmol/min per mg of protein. The Km for ATP was 0.11 mM. Other nucleotides, such as GTP, CTP or ADP, could not substitute for ATP in supporting the Ca2+-activated nucleotidase activity. Increasing the K+ concentration from 0 to 100 mM caused a 2-fold activation of the Ca2+, Mg2+-ATPase. Trifluoperazine, W7 [N-(6-aminohexyl)-5-chloronaphthalene-1-sulphonamide] and vanadate inhibited the enzyme. The concentration of trifluoperazine and vanadate required for 50% inhibition of the ATPase were 52 microM and 28 microM respectively. Calmodulin, cyclic AMP, cyclic AMP-dependent protein kinase and inositol 1,4,5-trisphosphate had no effect on the ATPase. The properties of the Ca2+, Mg2+ -ATPase were distinct from those of the Mg2+-ATPase, but comparable with those reported for the parotid endoplasmic-reticulum Ca2+-transport system [Kanagasuntheram & Teo (1982) Biochem. J. 208, 789-794]. The results suggest that the Ca2+, Mg2+-ATPase is responsible for driving the ATP-dependent Ca2+ accumulation by this membrane.

Ultrastructure of the Parotid Gland of the Nine-Banded Armadillo

1977 ◽  
Vol 35 ◽  
pp. 640-641
Author(s):  
J. R. Ruby
Keyword(s):  
Endoplasmic Reticulum ◽  
Parotid Gland ◽  
Periodic Acid ◽  
Acinar Cells ◽  
Duct System ◽  
Parotid Glands ◽  
Dasypus Novemcinctus ◽  
Anterior Portion ◽  
Periodic Acid Schiff ◽  
Thin Sections

Parotid glands were obtained from five adult (four male and one female) armadillos (Dasypus novemcinctus) which were perfusion-fixed. The glands were located in a position similar to that of most mammals. They extended interiorly to the anterior portion of the submandibular gland.In the light microscope, it was noted that the acini were relatively small and stained strongly positive with the periodic acid-Schiff (PAS) and alcian blue techniques, confirming the earlier results of Shackleford (1). Based on these qualities and other structural criteria, these cells have been classified as seromucous (2). The duct system was well developed. There were numerous intercalated ducts and intralobular striated ducts. The striated duct cells contained large amounts of PAS-positive substance.Thin sections revealed that the acinar cells were pyramidal in shape and contained a basally placed, slightly flattened nucleus (Fig. 1). The rough endoplasmic reticulum was also at the base of the cell.

scholarly journals Localization of Connexin 26, 32 and 43 in Rat Parotid Glands.

1998 ◽  
Vol 31 (3) ◽  
pp. 211-216 ◽  
Author(s):  
Chan Young Lee ◽  
Takashi Muramatsu ◽  
Masaki Shimono
Keyword(s):  
Connexin 26 ◽  
Parotid Glands ◽  
Rat Parotid

scholarly journals Changing myoepithelial cell distribution during regeneration of rat parotid glands.

2001 ◽  
Vol 80 (5) ◽  
pp. 283-290 ◽  
Author(s):  
Shigeru Takahashi ◽  
Shiro Nakamura ◽  
Reiko Suzuki ◽  
Takanori Domon ◽  
Tsuneyuki Yamamoto ◽  
...  
Keyword(s):  
Myoepithelial Cell ◽  
Cell Distribution ◽  
Parotid Glands ◽  
Rat Parotid

Intracellular Elemental Concentrations in Resting and Secreting Rat Parotid Glands

1987 ◽  
Vol 66 (2) ◽  
pp. 537-540 ◽  
Author(s):  
K.T. Izutsu ◽  
D.E. Johnson ◽  
M. Goddard
Keyword(s):  
Secretory Granules ◽  
Dry Weight ◽  
Parotid Glands ◽  
X Ray ◽  
Elemental Concentrations ◽  
Saliva Secretion ◽  
Concentration Changes ◽  
Rat Parotid ◽  
Micro Analysis

Electron probe x-ray micro-analysis was used to study the elemental concentration changes that occur during pilocarpine-stimulated saliva secretion. Quantitative x-ray micro-analysis of elemental concentrations in intracellular compartments of rat parotid glands stimulated in vivo with pilocarpine showed that Na concentration was significantly increased, while K concentration was significantly reduced. The magnitude of these changes was consistent with values obtained in other tissues with the x-ray micro-analysis method, and in the same tissue with other experimental methods. Comparisons with results from studies utilizing dispersed acini suggest that acinar dispersion procedures may affect intracellular elemental concentrations. Total electrolyte concentrations in cytoplasm and secretory granules were estimated to increase on a dry-weight basis following pilocarpine stimulation. The former change is consistent with the notion of a trans-cellular route of salivary fluid flow, while the latter change may be important in the exocytosis of secretory granules.

Association between microtubules and Golgi vesicles isolated from rat parotid glands

1990 ◽  
Vol 70 (3) ◽  
pp. 143-152 ◽  
Author(s):  
Gérard Coffe ◽  
Marie-Noëlle Raymond
Keyword(s):  
Parotid Glands ◽  
Golgi Vesicles ◽  
Rat Parotid

Isoproterenol downregulation of statin-related gene expression in the rat parotid gland

1991 ◽  
Vol 100 (3) ◽  
pp. 641-647
Author(s):  
D.K. Ann ◽  
A. Wechsler ◽  
H.H. Lin ◽  
E. Wang
Keyword(s):  
Parotid Gland ◽  
Nuclear Protein ◽  
Immunofluorescence Microscopy ◽  
Nuclear Staining ◽  
Parotid Glands ◽  
Cells In Culture ◽  
Indirect Immunofluorescence Microscopy ◽  
Wide Range ◽  
Parotid Cells ◽  
Rat Parotid

Statin, a 57 kilodalton (kDa) nuclear protein, is characteristically found in nonproliferating cells in culture as well as nondividing cells of a wide range of highly differentiated tissues. Moreover, cells in culture that are statin positive lose this statin expression when re-entering the cell-cycle traverse. In this work, statin expression was investigated in the parotid gland of untreated rats and those treated with isoproterenol (IPR), a proliferation-inducing catecholamine. Indirect immunofluorescence microscopy revealed specific nuclear staining with anti-statin monoclonal antibody (S-44) in the acinar and ducts cells of the untreated rats but significantly reduced in those induced with isoproterenol. To characterize the protein recognized by S-44, protein extracts from both tissues were immunoblotted and incubated with S-44. The antibody reacted specifically with a 48 kDa protein in the extract of the parotid glands from untreated rats while no reaction was detected in that of the proliferation-induced ones. These observations along with the result that a statin-like (S1) transcript is downregulated by isoproterenol in the parotid glands further support the notion that the disappearance of statin-related expression is associated with the IPR-induced proliferation in the rat parotid glands. The discrepancy between the apparent molecular mass of the protein identified by S-44 in nonproliferating parotid cells and that of statin originally found in fibroblasts, suggests that either a modified form of statin may be present in the parotid gland, or this 48 kDa protein may be a member of the nonproliferative statin-like family.

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