scholarly journals Uptake and efflux of 3-O-methyl-D-glucose in rat parotid cells

2013 ◽  
Vol 1 (4) ◽  
pp. 638-640 ◽  
Author(s):  
CEDRIC JURYSTA ◽  
KARIM LOUCHAMI ◽  
WILLY J. MALAISSE ◽  
ABDULLAH SENER
Keyword(s):  
Parotid Cells ◽  
Rat Parotid

scholarly journals Multiple transduction mechanisms are likely involved in calcium-mediated exocrine secretory events in rat parotid cells.

1983 ◽  
Vol 258 (5) ◽  
pp. 2774-2777
Author(s):  
L Bodner ◽  
M T Hoopes ◽  
M Gee ◽  
H Ito ◽  
G S Roth ◽  
...  
Keyword(s):  
Parotid Cells ◽  
Transduction Mechanisms ◽  
Rat Parotid

scholarly journals Properties of receptor-controlled inositol trisphosphate formation in parotid acinar cells

1985 ◽  
Vol 225 (1) ◽  
pp. 263-266 ◽  
Author(s):  
D L Aub ◽  
J W Putney
Keyword(s):  
Inositol Phosphates ◽  
Inositol Trisphosphate ◽  
Calcium Ionophore ◽  
Acinar Cells ◽  
Receptor Occupancy ◽  
Parotid Acinar Cells ◽  
Parotid Cells ◽  
Rat Parotid ◽  
K Release ◽  
Substance P Receptors

Activation of muscarinic receptors in rat parotid cells results in breakdown of polyphosphoinositides liberating inositol phosphates, including inositol trisphosphate. Formation of inositol trisphosphate appears independent of agonist-induced Ca2+ mobilization, since neither formation nor degradation of inositol trisphosphate are appreciably altered in low-calcium media, and elevation of cytosolic Ca2+ with a calcium ionophore does not cause an increase in cellular inositol trisphosphate. Further, activation of substance P receptors and alpha 1-adrenoreceptors, but not beta-adrenoreceptors, increases inositol trisphosphate formation. The dose-response curve for methacholine activation of inositol trisphosphate formation more closely approximates the curve for receptor occupancy than for Ca2+-activated K+ release. These results are all consistent with the suggestion that inositol trisphosphate could function as a second messenger linking receptor occupation to cellular Ca2+ mobilization.

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.

scholarly journals Modulation of extracellular ATP-induced Ca2+ responses: role of protein kinases

1993 ◽  
Vol 295 (1) ◽  
pp. 255-261 ◽  
Author(s):  
L Tenneti ◽  
B R Talamo
Keyword(s):  
Protein Kinase ◽  
Protein Kinases ◽  
Kinase Inhibitors ◽  
Extracellular Atp ◽  
Kinase C ◽  
Parotid Cells ◽  
Specific Permeability ◽  
Rat Parotid ◽  
Pharmacological Manipulations

Evidence for the modulation of the P2z-purinoceptor for extracellular ATP in dissociated rat parotid cells is presented in studies using compounds that inhibit protein kinases. Preincubation of acinar cells with the protein kinase catalytic-site inhibitors K-252a and staurosporine, as well as with the regulatory-domain inhibitor sphingosine, specifically potentiates the elevation in cytosolic Ca2+ concentration ([Ca2+]i) mediated by extracellular ATP, but has no effect on the [Ca2+]i elevation mediated by muscarinic receptors through phospholipase C activation. Phorbol dibutyrate (PDBu), which activates protein kinase C (PKC), has no modulatory effect on ATP-mediated [Ca2+]i elevation. Further, pretreatment with PDBu does not reverse or block the effects of K-252a or sphinogosine, arguing against the involvement of PKC. Other pharmacological manipulations indicate that neither calmodulin-dependent nor cyclic-AMP-dependent kinases are involved. Neither the peak intracellular Ca2+ mobilization nor the sustained Ca2+ entry in response to carbachol or to a Ca2+ ionophore (4-bromo-A23187) is altered by the kinase inhibitors that potentiate the [Ca2+]i response to ATP, indicating that effects on the ATP response are not due to non-specific permeability changes, nor to decreased Ca2+ removal from the cytosol. ATP-mediated influx of Mn2+ as well as ATP-induced membrane depolarization are potentiated in cells preincubated with K-252a, directly demonstrating that cation influx is enhanced through a P2z-specific route. These results show that P2z responses (or purinoceptors) can be modulated and suggest that phosphorylation events are involved.

scholarly journals Studies on rat parotid-cell actomyosin

1984 ◽  
Vol 220 (1) ◽  
pp. 291-299 ◽  
Author(s):  
T Kealey ◽  
P J Randle
Keyword(s):  
Affinity Chromatography ◽  
Light Chain ◽  
Myosin Light Chain Kinase ◽  
Myosin Light Chain ◽  
Bovine Brain ◽  
Cell Protein ◽  
Collagenase Digestion ◽  
Heat Treated ◽  
Parotid Cells ◽  
Rat Parotid

Actomyosin was partially purified from rat parotid cells dispersed by collagenase digestion and found to possess different solubility characteristics from that from (undispersed) rat parotid tissue. This is attributed to the decrease in vascular contamination effected by the isolation of parotid cells, yielding a non-muscle actomyosin [Adelstein, Conti, Johnson, Pastan & Pollard (1972) Proc. Natl. Acad. Sci. U.S.A. 69, 3693-3697]. Myosin light-chain kinase was partially purified from dispersed rat parotid cells by calmodulin affinity chromatography and shown to be activated by Ca2+-calmodulin. The calmodulin content of dispersed rat parotid cells was shown to be 6.50 +/- 0.59 ng of calmodulin/micrograms of rat parotid-cell protein (mean +/- S.E.M.), as determined by the activation of purified bovine brain phosphodiesterase by heat-treated extracts of dispersed rat parotid cells.

scholarly journals Phosphorylation of elongation factor 2 during Ca2+-mediated secretion from rat parotid acini

1992 ◽  
Vol 282 (3) ◽  
pp. 877-882 ◽  
Author(s):  
M T Hincke ◽  
A C Nairn
Keyword(s):  
Protein Synthesis ◽  
Phorbol Esters ◽  
Elongation Factor ◽  
Ionophore A23187 ◽  
Inhibit Protein Synthesis ◽  
Parotid Acinar Cells ◽  
Kinase C ◽  
Elongation Factor 2 ◽  
Parotid Cells ◽  
Rat Parotid

In this paper we report the rapid phosphorylation of a cytosolic 100 kDa protein during stimulation of secretion from dispersed aggregates of parotid acinar cells with Ca(2+)-mobilizing secretagogues (carbachol, Substance P, ATP and the Ca2+ ionophore A23187). Phosphorylation was inhibited by removal of extracellular Ca2+ but was not observed during stimulation with phorbol esters, suggesting that this protein is not a substrate for protein kinase C. Two-dimensional PAGE and immunoprecipitation with a specific antiserum indicated that this protein is elongation factor 2, whose Ca2+ calmodulin-dependent phosphorylation has been shown to inhibit protein synthesis [Nairn & Palfrey (1987) J. Biol. Chem. 262, 17299-17303]. These results suggest that phosphorylation of elongation factor 2 is the molecular mechanism for the inhibition of protein synthesis which has been previously observed in rat parotid cells during stimulation with Ca(2+)-mobilizing secretagogues.

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