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

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.

1991 ◽  
Vol 39 (8) ◽  
pp. 1077-1087 ◽  
Author(s):  
H Tamaki ◽  
S Yamashina

We studied the ultrastructure and cytochemistry of mitotic parotid acinar cells in vivo after induction of mitosis by isoproterenol injection. With entrance of the cells into the division cycle, the Golgi apparatus lost its characteristic stacked structure and internal polarity among the cisternae, appearing as fragments distributed throughout the cytoplasm. These fragments consisted of electron-lucent vesiculotubular structures and electron-dense 70-nm vesicles; neither component showed thiamine pyrophosphatase activity, a marker for trans cisternae of the Golgi apparatus, but the 70-nm vesicles showed a positive reaction for osmium impregnation, indicating retention of the cis nature. The rough endoplasmic reticulum was dilated and fragmented. Recovery of the structure of Golgi apparatus and rearrangement of rough endoplasmic reticulum occurred in daughter cells during telophase. These changes were the same as those observed after drug-induced inhibition of protein transport. The secretory granules were not dispersed but were divided into two groups with which centrioles were closely associated. Both groups migrated with the centrioles as far as the next interphase. The distribution of 5'-nucleotidase on the luminal plasma membrane showed no change during the process of division, thus demonstrating that surface polarity was maintained during mitosis. These changes in organelle structure and distribution may be due to the conversion of cell function from a secretory to a mitotic action.


1984 ◽  
Vol 32 (5) ◽  
pp. 477-485 ◽  
Author(s):  
A I Doine ◽  
C Oliver ◽  
A R Hand

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.


1977 ◽  
Vol 74 (2) ◽  
pp. 399-413 ◽  
Author(s):  
AR Hand ◽  
C Oliver

The method of secretory granuleformation in the acinar cells of the rat exorbital lacrimal gland was studied by electron microscope morphological and cytochemical techniques. Immature secretory granules at the inner face of the Golgi apparatus were frequently attached to a narrow cisternal structure similar to GERL as described in neurons by Novikoff et al. (Novikoff, P. M., A. B. Novikoff, N. Quintana, and J.-J. Hauw. 1971. J. Cell Bio. 50:859-886). In the lacrimal gland. GERL was located adjacent to the inner Golgi saccule, or separated from it by a variable distance. Portions of GERL were often closely paralleled by modified cisternae of rough endoplasmic reticulum (RER), which lacked ribosomes on the surface adjacent to GERL. Diaminobenzidine reaction product of the secretory enzyme peroxidase was localized in the cisternae of the nuclear envelope, RER, peripheral Golgi vesicles, Golgi saccules, and immature and mature secretory granules. GERL was usually free of peroxidase reaction product or contained only a small amount. Thiamine pyrophosphatase reaction product was present in two to four inner Golgi saccules; occasionally, the innermost saccule was dilated and fenestrated, and contained less reaction product than the next adjacent saccule. Acid phosphatase (AcPase) reaction product was present in GERL, immature granules, and, rarely, in the innermost saccule, but not in the rest of the Golgi saccules. Thick sections of AcPase preparations viewed at 100 kV revealed that GERL consisted of cisternal, and fenestrated or tublular portions. The immature granules were attached to GERL by multiple connections to the tublular portions. These results suggest that, in the rat exorbital lacrimal gland, the Golgi saccules participate in the transport of secretory proteins, and that GERL is involved in the formation of secretory granules.


1987 ◽  
Vol 35 (5) ◽  
pp. 565-570 ◽  
Author(s):  
C Oliver ◽  
Y Yuasa

We examined the distribution of trimetaphosphatase (TMPase)-positive basal lysosomes in pancreas, parotid, submandibular, sublingual, and exorbital lacrimal glands from rats, rabbits, and guinea pigs. The location of the basal lysosomes was compared to that of the acid phosphatase (AcPase)-positive lysosomes. In all of the tissues examined from rat and rabbit, AcPase activity was localized primarily to the Golgi region. Reaction product was localized in GERL, immature secretory granules, and lysosomes lying adjacent to the Golgi apparatus. TMPase activity was found in basal lysosomes and in occasional elongated lysosomes adjacent to the Golgi apparatus. In guinea pig, the distribution of TMPase activity was identical to that seen in the other two species, but a significant number of lysosomes in the basal region of the cells also contained AcPase activity. These results confirm and extend our previous finding (J Histochem Cytochem 31:1209, 1983) that exocrine acinar cells possess two distinct populations of lysosomes. The lysosomes in the Golgi region contain both AcPase and TMPase activity, whereas those in the basal portion of the cells are reactive predominantly for TMPase. The functional significance of the two populations of lysosomes is not understood at present.


2002 ◽  
Vol 50 (12) ◽  
pp. 1611-1623 ◽  
Author(s):  
Hideaki Tamaki ◽  
Shohei Yamashina

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.


1982 ◽  
Vol 242 (5) ◽  
pp. G481-G485 ◽  
Author(s):  
R. Henriksson

To determine whether beta 1- and beta 2-adrenoceptors have similar functions in salivary glands, Sprague-Dawley rats were chronically treated with either the beta 1-selective (prenalterol), beta 2-selective (terbutaline), or the nonselective beta-agonist isoproterenol. All three agonists increased parotid and submandibular gland weight and acinar cell size. Isoproterenol and prenalterol caused marked quantitative and qualitative alterations in the granule population, whereas terbutaline had no effect. A single injection of isoproterenol caused a significant amylase release and accumulation of cAMP. Prenalterol was as potent as isoproterenol with regard to amylase release but was without effect on the cAMP content. In contrast, terbutaline had a minimal effect on amylase release but had the same effect as isoproterenol on cAMP accumulation. The in vitro perifusion experiments confirmed these in vivo results with respect to the effects of the selective beta-agonists. Thus, the present investigation using both morphological and biochemical methods suggests that beta 1- and beta 2-adrenoceptors may have different functions in rat parotid acinar cells. In addition, the stimulus-growth coupling seems to be unrelated to stimulus-secretion coupling.


1983 ◽  
Vol 31 (8) ◽  
pp. 1041-1048 ◽  
Author(s):  
C Oliver ◽  
A R Hand

The distribution of thiamine pyrophosphatase (TPPase) and acid phosphatase (AcPase) has been examined in resting parotid acinar cells as well as during decreased and increased secretory granule production. In resting acinar cells, TPPase activity was restricted to the trans Golgi saccules and AcPase activity was localized in GERL and immature secretory granules. Although secretory granule production is diminished during ethionine intoxication, no significant alteration in the distribution of either TPPase or AcPase was noted. However, marked changes in enzyme localization, especially of TPPase, occurred during accelerated secretory granule production. The alterations were essentially the same for all of the conditions studied (recovery from ethionine treatment, recovery from a protein depletion diet, secretory stimulation with isoproterenol, and postnatal maturation of the parotid gland). During maximal secretory granule production, TPPase activity was localized not only in the trans Golgi saccules, but also in GERL-like cisternae and immature secretory granules. The immature secretory granules were often in continuity with the GERL-like cisternae. At the same time that the TPPase activity was increased, the AcPase activity was frequently diminished. These modulations in enzyme activity provide evidence that GERL is derived from the trans Golgi saccule.


2015 ◽  
Vol 60 (4) ◽  
pp. 642-649 ◽  
Author(s):  
Osamu Katsumata-Kato ◽  
Megumi Yokoyama ◽  
Miwako Matsuki-Fukushima ◽  
Takanori Narita ◽  
Hiroshi Sugiya ◽  
...  

1974 ◽  
Vol 16 (2) ◽  
pp. 309-331
Author(s):  
J. M. RADLEY

The mitotic arrest of acinar cells in the rat parotid gland in response to isoprenaline has been investigated at the ultrastructural level. The arrested cells were characterized by the presence of both centriole pairs at the cell centre, around which chromosomes formed an approximately spherical array. Microtubules radiated out from both centriole pairs, indicating that they were part of a bipolar system. The microtubule population included both non-kinetochore and kinetochore microtubules. Metaphase arrest appeared to be due to failure of the poles to separate, or to remain separated in the case of cells already in metaphase at the time of drug administration. This could be explained by the drug interfering with the ability of interpolar microtubules from opposite poles to interact with one another. The distribution of the chromosomes around the centrioles appears to depend on the presence of kinetochore microtubules, which are thought to act as tethers, either by themselves or in conjunction with non-kinetochore microtubules. It is suggested that tension is necessary between the kinetochores and poles to attain the arrest configuration. Chromosomes were observed in which both kinetochores had attached microtubules but whether or not they were linked to opposite poles remains to be investigated. Two types of arrested cell were distinguished by their content of secretory granules. Cells already in mitosis at the time of isoprenaline administration were not depleted by drug action, and during the period of arrest numerous large secretory granules were intermingled with the chromosomes. Those cells which entered mitosis after the drug was given were initially blocked in the G2 phase, during which time they were depleted of secretory granules. On entering mitosis, these cells possessed only small secretory granules, which were newly synthesized. In the metaphase-arrested state the small secretory granules were clustered around the centriolar complexes, demonstrating the presence of a poleward force operating on them. It is possible that the same force acts on the secretory granules in the first type of arrested cell, but because of the relatively large size of the granules, the clustering around the poles is not pronounced. The nature of the forces acting on the chromosomes and on the secretory granules is discussed. The functioning of these forces during the arrest state has to be considered in any general model for mitosis.


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