scholarly journals Immunocytochemical localization of renin in juxtaglomerular cells.

1985 ◽  
Vol 33 (4) ◽  
pp. 323-332 ◽  
Author(s):  
J Lacasse ◽  
M Ballak ◽  
C Mercure ◽  
J Gutkowska ◽  
C Chapeau ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Rough Endoplasmic Reticulum ◽  
Golgi Complex ◽  
Secretory Granules ◽  
Protein A ◽  
Secretory Proteins ◽  
Juxtaglomerular Cells ◽  
Newborn Mice ◽  
Sequence Of Events ◽  
Flocculent Material

The involvement of various organelles in the synthesis, transport, and packaging of renin in the juxtaglomerular cells of newborn mice has been investigated by immunocytochemistry with the protein A-gold technique. Highly specific rabbit antibodies against mouse submandibular renin were used. Mild fixation and embedding in glycol methacrylate allowed enough sensitivity to identify a steep gradient of labeling from rough endoplasmic reticulum to Golgi complex to secretory granules. Routine fixation and embedding in Epon produced labeling differentials that allowed delineation of hitherto ill-defined types of secretory granules and vacuoles. The classical pattern of synthesis, transport, and packaging of secretory proteins involves the rough endoplasmic reticulum and Golgi complex and seems to apply to renin secretion. Immunoreactive renin is packaged as rhomboid crystals at the trans face of the Golgi complex. The limiting membrane of these rhomboids fuses to form coalescing protogranules where the crystals eventually yield their individuality maturing into secretory granules. Vacuoles containing a flocculent material, with or without a dense core, show significant immunocytochemical labeling. These vacuoles are not associated with the Golgi complex but occupy cytoplasmic areas well endowed with rough endoplasmic reticulum. As judged from their morphological features and their immunoreactivity, the vacuoles do not seem to follow the sequence of events typical of protogranules and coalescing protogranules. They possibly represent a parallel pathway of renin synthesis and transport, involving the nuclear envelope and bypassing the Golgi complex.

The human fetal pituitary: An ultrastructural analysis

1983 ◽  
Vol 41 ◽  
pp. 574-575
Author(s):  
S. L. Asa ◽  
K. Kovacs ◽  
E. Horvath ◽  
F. A. Laszlo ◽  
I. Domokos
Keyword(s):  
Endoplasmic Reticulum ◽  
Rough Endoplasmic Reticulum ◽  
Secretory Granules ◽  
Type I ◽  
Hormone Production ◽  
Glycoprotein Hormone ◽  
Poorly Differentiated ◽  
Rathke's Cleft ◽  
Flocculent Material ◽  
Cytoplasmic Glycogen

An ultrastructural study was performed on 25 human fetal pituitaries to document the development of cell differentiation and hormone production in the adenohypophysis.At 5 weeks' gestation, Rathke's cleft was lined by columnar epithelium 3-4 cells deep (Fig. 1). The cells were poorly differentiated, with abundant cytoplasmic glycogen, numerous free ribosomes and occasional secretory granules. Terminal bars were formed on the lateral cell surfaces near the luminal surface of Rathke's cleft; desmosomes formed junctions between cells.By 6 weeks' gestation, cells resembling corticotrophs were identified (Fig. 2). They contained moderately developed, rough endoplasmic reticulum and numerous secretory granules of variable size, shape and electron density. In 8-week-old fetuses, type I microfilaments were found in those cells. Welldifferentiated somatotrophs were seen in the adenohypophyses of 8-9-week-old fetuses. They contained scattered profiles of rough-surfaced endoplasmic reticulum and spherical, evenly electron dense secretory granules, measuring 300-600 nm in diameter. Cells with dilated rough endoplasmic reticulum containing flocculent material and small, dense, round secretory granules with peripheral electron lucent halos were seen in the adenohypophysis of a 14-week-old fetus; these features are characteristic of the glycoprotein hormone cell line. Typical prolactin cells were not recognizable before 23 weeks' gestation.

scholarly journals Quantitative immunocytochemical localization of pancreatic secretory proteins in subcellular compartments of the rat acinar cell.

1980 ◽  
Vol 28 (2) ◽  
pp. 149-160 ◽  
Author(s):  
M Bendayan ◽  
J Roth ◽  
A Perrelet ◽  
L Orci
Keyword(s):  
Endoplasmic Reticulum ◽  
Rough Endoplasmic Reticulum ◽  
Protein A ◽  
Secretory Proteins ◽  
Zymogen Granules ◽  
Thin Sections ◽  
Intracellular Compartments ◽  
Rat Exocrine Pancreas ◽  
Acinar Lumen ◽  
Cellular Compartments

The recently developed protein A-gold technique for the detection of intracellular antigenic sites on thin sections was utilized to localize nine different secretory proteins in the rat exocrine pancreas. Amylase, chymotrypsinogen, trypsinogen, lipase, elastase, carboxypeptidases A and B, RNase and DNase, were detected at the level of the rough endoplasmic reticulum, the Golgi area, and the zymogen granules of the acinar cells, as well as in the acinar lumen. A quantitative evaluation of the labeling showed that its intensity was not identical for all enzymes studied nor in all cellular compartments analyzed. An increasing gradient of the labeling from the rough endoplasmic reticulum to the Golgi and to the zymogen granules was found for amylase, carboxypeptidases A and B, chymotrypsinogen, trypsinogen, and RNase, while a comparable low degree of labeling in the Golgi apparatus and in the zymogen granules was observed for DNase, lipase, and elastase. These results suggest that the nine enzymes are processed through the same intracellular compartments, but that they may be concentrated to different degrees in the zymogen granules before being released in the acinar lumen.

scholarly journals A vesicular intermediate in the transport of hepatoma secretory proteins from the rough endoplasmic reticulum to the Golgi complex.

1987 ◽  
Vol 104 (2) ◽  
pp. 221-230 ◽  
Author(s):  
H F Lodish ◽  
N Kong ◽  
S Hirani ◽  
J Rasmussen
Keyword(s):  
Endoplasmic Reticulum ◽  
Rough Endoplasmic Reticulum ◽  
Golgi Complex ◽  
Supernatant Fraction ◽  
Secretory Proteins ◽  
Golgi Vesicles ◽  
Intermediate Fraction ◽  
Intermediate Compartment ◽  
Alpha 1 Antitrypsin ◽  
Endoglycosidase H

We have identified a vesicle fraction that contains alpha 1-antitrypsin and other human HepG2 hepatoma secretory proteins en route from the rough endoplasmic reticulum (RER) to the cis face of the Golgi complex. [35S]Methionine pulse-labeled cells were chased for various periods of time, and then a postnuclear supernatant fraction was resolved on a shallow sucrose-D2O gradient. This intermediate fraction has a density lighter than RER or Golgi vesicles. Most alpha 1-antitrypsin in this fraction (P1) bears N-linked oligosaccharides of composition similar to that of alpha 1-antitrypsin within the RER; mainly Man8GlcNac2 with lesser amounts of Man7GlcNac2 and Man9GlcNac2; this suggests that the protein has not yet reacted with alpha-mannosidase-I on the cis face of the Golgi complex. This light vesicle species is the first post-ER fraction to be filled by labeled alpha 1-antitrypsin after a short chase, and newly made secretory proteins enter this compartment in proportion to their rate of exit from the RER and their rate of secretion from the cells: alpha 1-antitrypsin and albumin faster than preC3 and alpha 1-antichymotrypsin, faster, in turn, then transferrin. Deoxynojirimycin, a drug that blocks removal of glucose residues from alpha 1-antitrypsin in the RER and blocks its intracellular maturation, also blocks its appearance in this intermediate compartment. Upon further chase of the cells, we detect sequential maturation of alpha 1-antitrypsin to two other intracellular forms: first, P2, a form that has the same gel mobility as P1 but that bears an endoglycosidase H-resistant oligosaccharide and is found in a compartment--probably the medial Golgi complex--of density higher than that of the intermediate that contains P1; and second, the mature sialylated form of alpha 1-antitrypsin.

Ultrastructural Aspects of Golgi Complex Function in Parathyroid Cells of Winter Frogs

1973 ◽  
Vol 31 ◽  
pp. 680-681
Author(s):  
William J. Dougherty
Keyword(s):  
Golgi Complex ◽  
Secretory Granules ◽  
Complex Function ◽  
Secretory Activity ◽  
Secretory Proteins ◽  
Perivascular Spaces ◽  
Pituitary Cells ◽  
Electron Microscopic ◽  
Ca Ions ◽  
Regulation Of Secretion

The regulation of secretion in exocrine and endocrine cells has long been of interest. Electron microscopic and other studies have demonstrated that secretory proteins synthesized on ribosomes are transported by the rough ER to the Golgi complex where they are concentrated into secretory granules. During active secretion, secretory granules fuse with the cell membrane, liberating and discharging their contents into the perivascular spaces. When secretory activity is suppressed in anterior pituitary cells, undischarged secretory granules may be degraded by lysosomes. In the parathyroid gland, evidence indicates that the level of blood Ca ions regulates both the production and release of parathormone. Thus, when serum Ca is low, synthesis and release of parathormone are both stimulated; when serum Ca is elevated, these processes are inhibited.

scholarly journals DEVELOPMENT OF ENDOGENOUS PEROXIDASE IN FETAL RAT SUBMANDIBULAR GLAND

1973 ◽  
Vol 21 (1) ◽  
pp. 42-50 ◽  
Author(s):  
SHOHEI YAMASHINA ◽  
TIBOR BARKA
Keyword(s):  
Endoplasmic Reticulum ◽  
Nuclear Envelope ◽  
Submandibular Gland ◽  
Rough Endoplasmic Reticulum ◽  
Peroxidase Activity ◽  
Secretory Granules ◽  
Prenatal Development ◽  
Reaction Products ◽  
Cell Type ◽  
Endogenous Peroxidase

The prenatal development of endogenous peroxidase activity in the submandibular gland of rat was investigated by means of the diaminobenzidine-H2O2 histochemical method. The submandibular gland of a 16-day-old fetus was composed of cords of uniform, undifferentiated cells which contained no secretory granules and revealed no peroxidase activity. Peroxidase activity first appeared at the 17th day of gestation in the cisternae of the rough endoplasmic reticulum and nuclear envelope in a few cells. At the 18th day of gestation cells which exhibited reaction products in the rough endoplasmic reticulum and nuclear envelope also contained secretory granules with a strong peroxidase activity. During the last days of gestation the number of peroxidase positive cells, which contained numerous secretory granules, increased. The peroxidase-containing cells are the immediate precursors of the proacinar cells of early postnatal stages. During the same time period, when the peroxidase-containing cells differentiated, a second cell type also differentiated in the cellular cords. The development of this cell type was marked by the appearance of secretory granules stainable with toluidine blue. Through the prenatal development, this cell type revealed no peroxidase activity and was identified with the terminal tubule cell of the newborn. The morphologic and cytochemical findings indicate that terminal tubule cells and proacinar cells are committed cells; the former differentiate toward 2nd order intercalated duct cells and the latter transform to mature acinar cells.

scholarly journals Glycosyltransferase activities in Golgi complex and endoplasmic reticulum fractions isolated from African trypanosomes.

1984 ◽  
Vol 99 (2) ◽  
pp. 569-577 ◽  
Author(s):  
D J Grab ◽  
S Ito ◽  
U A Kara ◽  
L Rovis
Keyword(s):  
Endoplasmic Reticulum ◽  
Rough Endoplasmic Reticulum ◽  
Golgi Complex ◽  
Smooth Endoplasmic Reticulum ◽  
Surface Glycoprotein ◽  
Relative Distribution ◽  
African Trypanosomes ◽  
Independent Form ◽  
Variable Surface ◽  
Dependent Form

Highly enriched Golgi complex and endoplasmic reticulum fractions were isolated from total microsomes obtained from Trypanosoma brucei, Trypanosoma congolense, and Trypanosoma vivax, and tested for glycosyltransferase activity. Purity of the fractions was assessed by electron microscopy as well as by biochemical analysis. The relative distribution of all the glycosyltransferases was remarkably similar for the three species of African trypanosomes studied. The Golgi complex fraction contained most of the galactosyltransferase activity followed by the smooth and rough endoplasmic reticulum fractions. The dolichol-dependent mannosyltransferase activities were highest for the rough endoplasmic reticulum, lower for the smooth endoplasmic reticulum, and lowest for the Golgi complex. Although the dolichol-independent form of N-acetylglucosaminyltransferase was essentially similar in all the fractions, the dolichol-dependent form of this enzyme was much higher in the endoplasmic reticulum fractions than in the Golgi complex fraction. Inhibition of this latter activity in the smooth endoplasmic reticulum fraction by tunicamycin A1 suggests that core glycosylation of the variable surface glycoprotein may occur in this organelle and not in the rough endoplasmic reticulum as previously assumed.

scholarly journals THE ELABORATION OF PROTEIN AND CARBOHYDRATE BY RAT PARATHYROID CELLS AS REVEALED BY ELECTRON MICROSCOPE RADIOAUTOGRAPHY

1971 ◽  
Vol 51 (3) ◽  
pp. 596-610 ◽  
Author(s):  
K. Nakagami ◽  
H. Warshawsky ◽  
C. P. Leblond
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Intravenous Injection ◽  
Rough Endoplasmic Reticulum ◽  
Secretory Granules ◽  
Glycoprotein Precursor ◽  
Secretion Granules ◽  
And Migration ◽  
The One ◽  
Membrane Cell

The parathyroid glands of young rats were radioautographed after a single injection of the protein precursor tyrosine-3H in the hope of identifying the sites of synthesis and migration of newly formed protein in the gland cells. The same procedure was used after injection of the glycoprotein precursor galactose-3H. As early as 2 min after intravenous injection of tyrosine-3H, the label was mainly found in the rough endoplasmic reticulum suggesting that cisternal ribosomes are sites of protein synthesis. By 5 and 10 min, much of the label had migrated from the rough endoplasmic reticulum into the Golgi apparatus. By 20 and 30 min, some label had migrated from there into secretory granules. By 45 min and 1 hr, the label content of the cell had decreased, indicating release of labeled material outside the cell. At 2 min after intravenous injection of galactose-3H, the label was mainly present in the Golgi apparatus, where presumably galactose is taken up into glycoprotein. By 10 min, some label appeared in secretion granules and by 30 min release of the material to the outside of the cell was under way. In conclusion, it is likely that the tyrosine-labeled protein material consists mainly of the parathyroid hormone. The galactose-labeled carbohydrate material would be either associated with the hormone in the cell or be part of a distinct glycoprotein which may be the one present on the outer surface of the plasma membrane (cell coat).

scholarly journals Expression of Enamel Proteins in Rough Endoplasmic Reticulum and Golgi Complex in Human Dental Germs

2017 ◽  
Vol 35 (2) ◽  
pp. 435-441
Author(s):  
Francisco Javier Gutiérrez-Cantú ◽  
Alma Lilián Guerrero-Barrera ◽  
Wulfrano Sánchez Meraz ◽  
Amaury de Jesús Pozos-Guillen ◽  
Héctor Flores-Reyes ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Rough Endoplasmic Reticulum ◽  
Golgi Complex ◽  
Enamel Proteins
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