Cytochemical studies on the internal polarity of the golgi apparatus and the relationship between this organelle and GERL

Sawano, Fumio; Fujita, Hisao

doi:10.1007/bf00495880

Cited by 14 publications

(10 citation statements)

References 26 publications

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“…This data indicates the possibility that the iodination of tyrosine in thyroglobulin could occur not only in the follicle lumen but also in the cytoplasm, such as rough endoplasmic reticulum, Golgi apparatus and subapical vesicles. Secretory granules for thyroglobulin contain also peroxidase activity (24). As to the data obtained from the 125I autoradiography showing that iodination of tyrosine takes place almost entirely in the follicle lumen, the author considers that thyroglobulin in the follicle lumen is far larger in quantity than that in the cell cytoplasm and numerous molecules of thyroglobulin in the follicle lumen might have not yet been completely iodinated and therefore injected iodine is considered to be combined with luminal colloid preferentially (4).…”

Section: Localization Of Peroxidase Activitymentioning

confidence: 99%

“…Acid phosphatase activity is localized in primary and secondary lysosomes, small vesicles, multivesicular bodies, rigid lamellae and the cisternae of 1-2 saccules of trans-side of the Golgi apparatus (24). Small lysosomes, 100-300 nm in diameter and homogeneously dense, are primary lysosomes derived from the Golgi apparatus.…”

Section: Localization Of Acpase Activitymentioning

confidence: 99%

“…In addition to AcPase activity, thiamine pyrophosphatase (TPPase) activity is localized in the cisternae of 1-2 stacks of trans-side of the Golgi apparatus (24). This fact is common to the Golgi apparatus of all kinds of cells.…”

Section: Localization Of Acpase Activitymentioning

confidence: 99%

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Cytochemical aspects on the secretion mechanism of the thyroid gland.

Fujita

1981

Acta Histochem. Cytochem

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OrientationIn the thyroid hormones, triiodothyronine (T3) and thyroxine (T4) are not peptides but characteristic amino acid derivatives, derived from only two molecules of iodotyrosine linked by ether bond (-o-). In all the peptide-secreting cells, the secretory granule, which originates from the rough endoplasmic reticulum and Golgi apparatus system, is released into the connective tissue space. However, formation of T3 and T4 in the thyroid requires more complicated steps. The hormones are not synthesized directly from their constituents, tyrosine and iodine in the cell, but a part of their synthetic process takes place in the extracellular lumen, called the follicle lumen. The secretory process of T3 and T4 is as follows: (i) synthesis of a large molecular glycoprotein (MW 660,000), called thyroglobulin in the follicle epithelial cell, (ii) release of thyroglobulin into the follicle lumen, (iii) iodination of the tyrosyl residues of thyroglobulin, and coupling of iodotyrosine residues to make T3 or T4 in thyroglobulin, (iv) reabsorption of thyroglobulin from the follicle lumen into the follicle epithelial cell, (v) hydrolysis of thyroglobulin for the liberation of T3 and T4, and (vi) release of T3 and T4 from the follicle epithelial cell into the connective tissue space. The present paper deals with the outline of cytochemical aspects on the secretion mechanism of the thyroid gland, except for the parafollicular cell, which secretes a peptide hormone called thyrocalcitonin. Autoradiography of 3H-amino acidThe follicle epithelial cell has to synthesize a high-molecular-weight glycoprotein, called thyroglobulin. As in other protein secretory cells, the proteinous part of thyroglobulin is synthesized at the attached ribosomes of the well developed rough endoplasmic reticulum and is stored in the cisternae of this organelle. Then the synthesized protein is transported to the Golgi apparatus, where the secretory granules, about 200 nm in diameter, arise. By the electron microscopic autoradiography of 3H-amino acid, the intracellular route for the synthesis and release of thyroglobulin has been clarified (3,6,18). In our data, the labeled amino acid first appears in the cisternae of rough endoplasmic reticulum within 15 min after the intraperitoneal injection of 3H-leucine. Then the silver grains begin to appear in the Golgi apparatus and subapical vesicles (secretary granules) after 30-45 min and in the follicle lumen after 45 min (3, 6).The proteinous part of thyroglobulin has to be bound to carbohydrate elements to become a glycorpotein. Using electron microscopic autoradiography of 3H-mannose, 3H-galactose, and 3H-fucose, the problem concerning the site of incorpo-391

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Section: Localization Of Peroxidase Activitymentioning

confidence: 99%

Section: Localization Of Acpase Activitymentioning

confidence: 99%

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Cytochemical aspects on the secretion mechanism of the thyroid gland.

Fujita

1981

Acta Histochem. Cytochem

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“…Our present study concerns cytochemical aspects of the existence of internal polarity of the Golgi apparatus and the relationship between the Golgi apparatus and the GERL. apparatus (9). In addition to these, immature secretory granules are positive for TTPase in anterior pituitary cells and exocrine pancreatic cells (2,9).…”

Section: Introductionmentioning

confidence: 99%

“…In addition to these, immature secretory granules are positive for TTPase in anterior pituitary cells and exocrine pancreatic cells (2,9). Rigid lamellae are rarely positive for this reaction in anterior pituitary and adrenal medullary cells (9).…”

Section: Introductionmentioning

confidence: 99%