scholarly journals RADIOAUTOGRAPHIC STUDY OF IN VIVO AND IN VITRO INCORPORATION OF FUCOSE-3H INTO THYROGLOBULIN BY RAT THYROID FOLLICULAR CELLS

1971 ◽  
Vol 49 (3) ◽  
pp. 856-882 ◽  
Author(s):  
A. Haddad ◽  
Meredith D. Smith ◽  
Annette Herscovics ◽  
N. J. Nadler ◽  
C. P. Leblond
Keyword(s):  
Golgi Apparatus ◽  
Side Chains ◽  
Follicular Cells ◽  
Thyroid Follicular Cells ◽  
Apical Vesicles ◽  
Electron Microscopes ◽  
Rat Thyroid ◽  
Silver Grains

The incorporation of fucose-3H in rat thyroid follicles was studied by radioautography in the light and electron microscopes to determine the site of fucose incorporation into the carbohydrate side chains of thyroglobulin, and to follow the migration of thyroglobulin once it had been labeled with fucose-3H. Radioautographs were examined quantitatively in vivo at several times after injection of fucose-3H into rats, and in vitro following pulse-labeling of thyroid lobes in medium containing fucose-3H. At 3–5 min following fucose-3H administration in vivo, 85% of the silver grains were localized over the Golgi apparatus of thyroid follicular cells. By 20 min, silver grains appeared over apical vesicles, and by 1 hr over the colloid. At 4 hr, nearly all of the silver grains had migrated out of the cells into the colloid. Analysis of the changes in concentration of label with time showed that radioactivity over the Golgi apparatus increased for about 20 min and then decreased, while that over apical vesicles increased to reach a maximum at 35 min. Later, the concentration of label over the apical vesicles decreased, while that over the colloid increased. Similar results were obtained in vitro. It is concluded that fucose, which is located at the end of some of the carbohydrate side chains, is incorporated into thyroglobulin within the Golgi apparatus of thyroid follicular cells, thereby indicating that some of these side chains are completed there. Furthermore, the kinetic analysis demonstrates that apical vesicles are the secretion granules which transport thyroglobulin from the Golgi apparatus to the apex of the cell and release it into the colloid.

scholarly journals IN VIVO INCORPORATION OF 3H-GALACTOSE BY THYROID FOLLICULAR CELLS OF THE RAT, AS SHOWN BY ELECTRON MICROSCOPIC RADIOAUTOGRAPHY

1972 ◽  
Vol 20 (3) ◽  
pp. 220-224 ◽  
Author(s):  
A. HADDAD
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Rough Endoplasmic Reticulum ◽  
Side Chains ◽  
Follicular Cells ◽  
Electron Microscopic ◽  
Thyroid Follicular Cells ◽  
Apical Vesicles ◽  
Electron Microscopic Radioautography

Radioactive galactose was injected intravenously into rats and localized in thyroid follicular cells by electron microscopic radioautography at intervals ranging from 2.5 to 30 min after injection. The galactose label was mostly present in the Golgi apparatus at 2.5 min, with some of it in the adjacent rough endoplasmic reticulum. By 30 min, the label was found in apical vesicles and colloid. It was concluded that galactose is added to the carbohydrate side chains of incomplete thyroglobulin molecules during their travel through the cisternae of the endoplasmic reticulum into the Golgi apparatus; the uptake begins as this organelle is approached, but predominates within it. The thyroglobulin molecule which has thus been labeled is transported by the apical vesicles to the colloid.

scholarly journals RADIOAUTOGRAPHIC VISUALIZATION OF THE INCORPORATION OF GALACTOSE-3H AND MANNOSE-3H BY RAT THYROIDS IN VITRO IN RELATION TO THE STAGES OF THYROGLOBULIN SYNTHESIS

1969 ◽  
Vol 43 (2) ◽  
pp. 289-311 ◽  
Author(s):  
P. Whur ◽  
Annette Herscovics ◽  
C. P. Leblond
Keyword(s):  
Endoplasmic Reticulum ◽  
Electron Microscope ◽  
Golgi Apparatus ◽  
Rough Endoplasmic Reticulum ◽  
Light Microscope ◽  
Detectable Effect ◽  
Apical Vesicles ◽  
Rat Thyroid

Rat thyroid lobes incubated with mannose-3H, galactose-3H, or leucine-3H, were studied by radioautography. With leucine-3H and mannose-3H, the grain reaction observed in the light microscope is distributed diffusely over the cells at 5 min, with no reaction over the colloid. Later, the grains are concentrated towards the apex, and colloid reactions begin to appear by 2 hr. With galactose-3H, the reaction at 5 min is again restricted to the cells but it consists of clumped grains next to the nucleus. Soon after, grains are concentrated at the cell apex and colloid reactions appear in some follicles as early as 30 min. Puromycin almost totally inhibits incorporation of leucine-3H and mannose-3H, but has no detectable effect on galactose-3H incorporation during the 1st hr. Quantitation of electron microscope radioautographs shows that mannose-3H label localizes initially in the rough endoplasmic reticulum, and by 1–2 hr much of this reaction is transferred to the Golgi apparatus. At 3 hr and subsequently, significant reactions are present over apical vesicles and colloid, while the Golgi reaction declines. Label associated with galactose-3H localizes initially in the Golgi apparatus and rapidly transfers to the apical vesicles, and then to the colloid. These findings indicate that mannose incorporation into thyroglobulin precursors occurs within the rough endoplasmic reticulum; these precursors then migrate to the Golgi apparatus, where galactose incorporation takes place. The glycoprotein thus formed migrates via the apical vesicles to the colloid.

scholarly journals Localization of thyroglobulin antigenicity in rat thyroid sections using antibodies labled with peroxidase or (125)I-radioiodine

1977 ◽  
Vol 74 (3) ◽  
pp. 992-1015 ◽  
Author(s):  
J Paiement ◽  
CP Leblond
Keyword(s):  
Endoplasmic Reticulum ◽  
Rough Endoplasmic Reticulum ◽  
Follicular Cells ◽  
Lysosomal Degradation ◽  
High Concentration ◽  
Different Types ◽  
Apical Vesicles ◽  
Rat Thyroid ◽  
Silver Grains ◽  
Distinct Distribution

In the hope of localizing thyroglobulin within focullar cells of the thyroid gland, antibodies raised against rat thyroglobulin were labeled with the enzyme horseradish peroxidase or with (125)I-radioiodine. Sections of rat thyroids fixed in glutaraldehyde and embedded in glycol methacrylate or Araldite were placed in contact with the labeled antibodies. The sites of antibody binding were detected by diaminobenzidine staining in the case of peroxidase labeling, and radioautography in the case of 125(I) labeling. Peroxidase labeling revealed that the antibodies were bound by the luminal colloid of the thyroid follicles and, within focullar cells, by colloid droplets, condensing vacuoles, and apical vesicles. (125)I labeling confirmed these findings, and revealed some binding of antibodies within Golgi saccules and rough endoplasmic reticulum. This method provides a visually less distinct distribution than peroxidase labeling, but it allowed ready quantitation of the reactions by counts of silver grains in the radioautographs. The counts revealed that the concentration of label was similar in the luminal colloid of different follicles, but that it varied within the compartments of follicular cells. A moderate concentration was detected in rough endoplasmic reticulum and Golgi saccules, whereas a high concentration was found in condensing vacuoles, apical vesicles, and in the luminal colloid. Varying amounts of label were observed over the different types of colloid droplets, and this was attributed to various degrees of lysosomal degradation of thyroglobulin. It is concluded that the concentration of thyroglobulin antigenicity increases during transport from the ribosomal site of synthesis to the follicular colloid, and then decreases during the digestion of colloid droplets which leads to the release of the thyoid hormone.

Suppressing effect of cysteamine on the TSH-stimulated mitotic activity of the rat thyroid follicular cells in vivo

Neuropeptides ◽  
1989 ◽  
Vol 13 (3) ◽  
pp. 171-174 ◽  
Author(s):  
G. Zerek-Melen ◽  
E. Sewerynek ◽  
M. Szkudlinski ◽  
A. Lewinski ◽  
M. Krotewicz ◽  
...  
Keyword(s):  
Mitotic Activity ◽  
Follicular Cells ◽  
Thyroid Follicular Cells ◽  
Rat Thyroid

scholarly journals APPEARANCE AND FUNCTION OF ENDOGENOUS PEROXIDASE IN FETAL RAT THYROID

1971 ◽  
Vol 51 (1) ◽  
pp. 162-175 ◽  
Author(s):  
Judy M. Strum ◽  
Janice Wicken ◽  
John R. Stanbury ◽  
Morris J. Karnovsky
Keyword(s):  
Apical Cell ◽  
Thyroid Peroxidase ◽  
Follicular Cells ◽  
Thyroid Follicle ◽  
Apical Cell Membrane ◽  
Fetal Rat ◽  
Apical Vesicles ◽  
Rat Thyroid ◽  
And Function

Iodination within the thyroid follicle is intimately associated with a thyroid peroxidase. In order to locate the in vivo site of iodination, the initial cytochemical appearance of this enzyme has been determined in fetal rat thyroid and its presence correlated with the onset of iodinated thyroglobulin synthesis. Peroxidase first appears in follicular cells during the 18th day of gestation. It is seen first in the perinuclear cisternae, the cisternae of the endoplasmic reticulum, and within the inner few Golgi lamellae. These organelles presumably represent sites of peroxidase synthesis. During the 19th and 20th days of gestation, there is a tremendous increase in peroxidase activity. In addition to the stained sites described, there are now many peroxidase-positive apical vesicles in the follicular cells. Newly forming follicles stain most conspicuously for peroxidase, the reaction product being heavily concentrated at the external surfaces of apical microvilli and in the adjacent colloid. Iodinated thyroglobulin becomes biochemically detectable in thyroids during the 19th day of gestation and increases greatly during the 20th day. The parallel rise in peroxidase staining that just precedes, and overlaps, the rise in iodinated thyroglobulin, suggests that apical vesicles and the apical cell membrane are the major sites of iodination within the thyroid follicle.

scholarly journals Generation of Thyroid Tissues From Embryonic Stem Cells via Blastocyst Complementation In Vivo

2020 ◽  
Vol 11 ◽  
Author(s):  
Qingsong Ran ◽  
Qiliang Zhou ◽  
Kanako Oda ◽  
Akihiro Yasue ◽  
Manabu Abe ◽  
...  
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Embryonic Stem ◽  
Branching Morphogenesis ◽  
Compound Heterozygous ◽  
Follicular Cells ◽  
Blastocyst Complementation ◽  
Thyroid Follicular Cells

The generation of mature, functional, thyroid follicular cells from pluripotent stem cells would potentially provide a therapeutic benefit for patients with hypothyroidism, but in vitro differentiation remains difficult. We earlier reported the in vivo generation of lung organs via blastocyst complementation in fibroblast growth factor 10 (Fgf10), compound, heterozygous mutant (Fgf10 Ex1mut/Ex3mut) mice. Fgf10 also plays an essential role in thyroid development and branching morphogenesis, but any role thereof in thyroid organogenesis remains unclear. Here, we report that the thyroids of Fgf10 Ex1mut/Ex3mut mice exhibit severe hypoplasia, and we generate thyroid tissues from mouse embryonic stem cells (ESCs) in Fgf10 Ex1mut/Ex3mut mice via blastocyst complementation. The tissues were morphologically normal and physiologically functional. The thyroid follicular cells of Fgf10 Ex1mut/Ex3mut chimeric mice were derived largely from GFP-positive mouse ESCs although the recipient cells were mixed. Thyroid generation in vivo via blastocyst complementation will aid functional thyroid regeneration.

scholarly journals AUTORADIOGRAPHIC STUDIES OF SYNTHESIS AND INTRACELLULAR MIGRATION OF GLYCOPROTEINS IN THE RAT ANTERIOR PITUITARY GLAND

1974 ◽  
Vol 62 (1) ◽  
pp. 185-197 ◽  
Author(s):  
Georges Pelletier
Keyword(s):  
Golgi Apparatus ◽  
Secretory Granules ◽  
In Vivo Studies ◽  
Time Intervals ◽  
Electron Microscope Autoradiography ◽  
The Matrix ◽  
Silver Grains ◽  
Gonadotrophic Cells

The incorporation of [3H]fucose in the somatotrophic and gonadotrophic cells of the rat adenohypophysis has been studied by electron microscope autoradiography to determine the site of synthesis of glycoproteins and to follow the migration of newly synthesized glycoproteins. The pituitaries were fixed 5 min, 20 min, 1 h, and 4 h after the in vivo injection of [3H]fucose and autoradiographs analyzed quantitatively. At 5 min after [3H]fucose administration, 80–90% of the silver grains were localized over the Golgi apparatus in both somatotrophs and gonadotrophs. By 20 min, the Golgi apparatus was still labeled and some radioactivity appeared over granules. At 1 h and 4 h, silver grains were found predominantly over secretory granules. The kinetic analysis showed that in both protein-secreting cells (somatotrophs) and glycoprotein-secreting cells (gonadotrophs), the glycoproteins have their synthesis completed in the Golgi apparatus and migrate subsequently to the secretory granules. It is concluded from these in vivo studies that glycoproteins which are not hormones are utilized for the formation of the matrix and/or of the membrane of the secretory granules. The incorporation of [3H]fucose in gonadectomy cells (hyperstimulated gonadotrophs) was also studied in vitro after pulse labeling of pituitary fragments in medium containing [3H]fucose. The incorporation of [3H]fucose was localized in both the rough endoplasmic reticulum (ER) and the Golgi apparatus. Later, the radioactivity over granules increased while that over the Golgi apparatus decreased. The concentration of silver grains over the dilated cisternae of the rough ER was not found to be modified at the longest time intervals studied.

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