Morphological and cytochemical alterations of the Golgi apparatus and GERL in rat parotid acinar cells during ethionine intoxication and recovery

1980 ◽  
Vol 158 (3) ◽  
pp. 275-284 ◽  
Author(s):  
Constance Oliver ◽  
Regina E. Auth ◽  
Arthur R. Hand
Keyword(s):  
Golgi Apparatus ◽  
Acinar Cells ◽  
Parotid Acinar Cells ◽  
Rat Parotid

scholarly journals Structural Integrity of the Golgi Stack Is Essential for Normal Secretory Functions of Rat Parotid Acinar Cells: Effects of Brefeldin A and Okadaic Acid

2002 ◽  
Vol 50 (12) ◽  
pp. 1611-1623 ◽  
Author(s):  
Hideaki Tamaki ◽  
Shohei Yamashina
Keyword(s):  
Golgi Apparatus ◽  
Okadaic Acid ◽  
Cathepsin D ◽  
Structural Integrity ◽  
Brefeldin A ◽  
Acinar Cells ◽  
Ultrastructural Organization ◽  
Golgi Stack ◽  
Parotid Acinar Cells ◽  
Rat Parotid

We examined the effects of specific inhibitors, brefeldin A (BFA) and okadaic acid (OA), on the ultrastructural organization of the Golgi apparatus and distributions of amylase, Golgi-associated proteins, and cathepsin D in the rat parotid acinar cells. BFA induced a rapid regression of the Golgi stack into rudimentary Golgi clusters composed of tubulovesicules, in parallel with a redistribution of the Golgi-resident proteins and a coat protein (β-COP) into the region of the rough endoplasmic reticulum (rER) or cytosol. The rapid disruption of the Golgi stack could also be induced by the effect of OA. However, redistribution of the Golgi proteins in rER or cytosol could not be observed and β-COP was not dispersed but was retained on the rudimentary Golgi apparatus. These findings suggested that the mechanism of OA in inducing degeneration of the Golgi stack was markedly different from that of BFA. In addition, missorting of amylase, a Golgi protein, and cathepsin D into incorrect transport pathways is apparent in the course of the disruption of the Golgi stack by OA. These Golgi-disrupting effects are reversible and the reconstruction of the stacked structure of the Golgi apparatus started immediately after the removal of inhibitors. In the recovery processes, missorting was also observed until the integrated structure of the Golgi apparatus was completely reconstructed. This suggested that the integrated structure of the Golgi apparatus was quite necessary for the occurrence of normal secretory events, including proper sorting of molecules.

scholarly journals Effects of secretory stimulation on the Golgi apparatus and GERL of rat parotid acinar cells.

1984 ◽  
Vol 32 (4) ◽  
pp. 403-412 ◽  
Author(s):  
A R Hand ◽  
C Oliver
Keyword(s):  
Golgi Apparatus ◽  
Functional Relationship ◽  
Secretory Granules ◽  
Acinar Cells ◽  
Dynamic Nature ◽  
Parotid Acinar Cells ◽  
Golgi Region ◽  
Thiamine Pyrophosphatase ◽  
Rat Parotid

The structure and cytochemistry of the Golgi apparatus and GERL of rat parotid acinar cells was studied after in vivo secretory stimulation with isoproterenol. Discharge of mature secretory granules was complete within 1 hr after isoproterenol injection, but immature granules in the Golgi region or near the lumen were not released. At early times (1-5 hr) after isoproterenol, acid phosphatase (AcPase) activity was markedly increased in GERL and immature secretory granules compared to uninjected controls. GERL appeared increased in extent and numerous continuities with immature granules were observed. Reaccumulation of mature secretory granules was first evident at 5 hr, and was almost complete by 16 hr after isoproterenol. Thiamine pyrophosphatase (TPPase) activity, normally restricted to the trans Golgi saccules, was frequently present in immature granules during this time. Narrow cisternae resembling GERL, occasionally in continuity with immature granules, also contained TPPase reaction product. By 16-24 hr after stimulation, the activity and distribution of AcPase and TPPase were similar to control cells. These results demonstrate the dynamic nature of the Golgi apparatus and GERL in parotid acinar cells, and emphasize the close structural and functional relationship between these two structures.

scholarly journals The Golgi apparatus and GERL during postnatal differentiation of rat parotid acinar cells: an electron microscopic cytochemical study.

1984 ◽  
Vol 32 (5) ◽  
pp. 477-485 ◽  
Author(s):  
A I Doine ◽  
C Oliver ◽  
A R Hand
Keyword(s):  
Young Adult ◽  
Golgi Apparatus ◽  
Secretory Granules ◽  
Acinar Cells ◽  
Sprague Dawley ◽  
Electron Microscopic ◽  
Cytochemical Study ◽  
Parotid Acinar Cells ◽  
Postnatal Differentiation ◽  
Rat Parotid

Morphological and cytochemical changes in the Golgi apparatus and GERL of differentiating parotid acinar cells were examined in Sprague-Dawley rats from 5 days to young adult. At day 5, the Golgi apparatus consisted of 3-6 narrow saccules, with short segments of GERL lying adjacent to the trans Golgi saccule. As the glands matured, the Golgi apparatus increased in size and the saccules became broadened and fenestrated reaching a maximum from days 15-20. The saccules subsequently narrowed slightly and by day 25 resembled those seen in young adults. Numerous cisternae of GERL could be seen at the trans face during this period. While the glands were maturing, marked changes occurred in the distribution of thiamine pyrophosphatase (TPPase) activity in the Golgi saccules. In the immature cells, TPPase activity was restricted to 1 or 2 trans Golgi saccules. However, by day 10 TPPase could also be localized in immature secretory granules and in GERL-like cisternae. Unreactive segments of GERL were also present. This pattern of localization persisted until day 20, after which the TPPase activity in the GERL-like cisternae diminished gradually until by day 40 TPPase again was localized in 1-2 trans Golgi saccules and an occasional immature secretory granule. Acid phosphatase (AcPase) activity was localized primarily in lysosomes in the very young animals and increased in GERL with age up to day 15. From days 15 to 20 there was a decrease in the amount of activity seen in GERL, but from day 20 on, the AcPase activity increased until it reached that seen in young adult animals. These results indicate that the presence of TPPase activity in GERL-like cisternae and immature secretory granules may be dependent upon the developmental as well as the physiologic state of the acinar cells and lend further support to the suggestion that GERL is derived from the trans Golgi saccules.

scholarly journals β-Adrenergic stimulation alters oligosaccharide pyrophosphoryl dolichol metabolism in rat parotid acinar cells

1985 ◽  
Vol 231 (2) ◽  
pp. 431-438 ◽  
Author(s):  
S R Grant ◽  
E E Kousvelari ◽  
D K Banerjee ◽  
B J Baum
Keyword(s):  
Half Life ◽  
Specific Radioactivity ◽  
Acinar Cells ◽  
Protein Glycosylation ◽  
Significant Enhancement ◽  
Adrenergic Stimulation ◽  
Parotid Acinar Cells ◽  
Secretory Glycoproteins ◽  
Rat Parotid ◽  
Stimulation Of

beta-Adrenergic stimulation of rat parotid acinar cells markedly increases [3H]mannose incorporation into N-linked glycoproteins [Kousvelari, Grant, Banerjee, Newby & Baum (1984) Biochem. J. 222, 17-24]. More than 90% of this protein-bound [3H]mannose was preferentially incorporated into four secretory glycoproteins. The ratio of [3H]mannose/[14C]leucine present in these individual proteins was 1.7-4-fold greater with isoproterenol-treated cells than with untreated controls. In isoproterenol-stimulated cells, [3H]mannose incorporation into mannosylphosphoryl dolichol and oligosaccharide-PP-dolichol was increased 2-3-fold over that observed in unstimulated cells. Similarly, formation of mannosylated oligosaccharide-PP-dolichol was increased approx. 4-fold in microsomes prepared from isoproterenol-treated cells. Also, turnover of oligosaccharide-PP-dolichol was significantly increased (5-fold) by β-adrenergic stimulation; the half-life for oligosaccharide-PP-dolichol decreased from 6 min in control cells to 1.2 min in isoproterenol-stimulated cells. By 15 min after isoproterenol addition to acinar cells, the specific radioactivity of parotid oligosaccharide moieties increased about 3-fold over the value observed in the absence of the agonist. Taken together, these results strongly suggest that elevation of N-linked protein glycosylation in rat parotid acinar cells after β-adrenoreceptor stimulation resulted from significant enhancement in the synthesis of mannosylphosphoryl dolichol and oligosaccharide-PP-dolichol and the turnover of oligosaccharide-PP-dolichol.

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.

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