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 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 CYTOCHEMICAL LOCALIZATION OF ENDOGENOUS PEROXIDASE IN THYROID FOLLICULAR CELLS

1970 ◽  
Vol 44 (3) ◽  
pp. 655-666 ◽  
Author(s):  
Judy M. Strum ◽  
Morris J. Karnovsky
Keyword(s):  
Peroxidase Activity ◽  
Apical Cell ◽  
Thyroid Peroxidase ◽  
Follicular Cells ◽  
Cytochemical Localization ◽  
Thyroid Follicular Cells ◽  
Endogenous Peroxidase ◽  
Rat Thyroid ◽  
Vitro Effect

Endogenous peroxidase activity in rat thyroid follicular cells is demonstrated cytochemically. Following perfusion fixation of the thyroid gland, small blocks of tissue are incubated in a medium containing substrate for peroxidase, before being postfixed in osmium tetroxide, and processed for electron microscopy. Peroxidase activity is found in thyroid follicular cells in the following sites: (a) the perinuclear cisternae, (b) the cisternae of the endoplasmic reticulum, (c) the inner few lamellae of the Golgi complex, (d) within vesicles, particularly those found apically, and (e) associated with the external surfaces of the microvilli that project apically from the cell into the colloid. In keeping with the radioautographic evidence of others and the postulated role of thyroid peroxidase in iodination, it is suggested that the microvillous apical cell border is the major site where iodination occurs. However, that apical vesicles also play a role in iodination cannot be excluded. The in vitro effect of cyanide, aminotriazole, and thiourea is also discussed.

A reinvestigation of the function of the mammalian urinary bladder

1977 ◽  
Vol 232 (3) ◽  
pp. F187-F195 ◽  
Author(s):  
S. A. Lewis
Keyword(s):  
Urinary Bladder ◽  
Membrane Surface ◽  
Apical Cell ◽  
Membrane Damage ◽  
In Vitro Experiments ◽  
Apical Cell Membrane ◽  
Cell Membrane Damage ◽  
Using Data

The function of adult mammalian urinary bladder is evaluated in light of recent in vitro experiments. The discrepancy between in vivo and in vitro experimental results is examined and a possible solution proposed. Techniques for eliminating edge damage and measuring apical membrane surface area are described. A new chamber design for microelectrode studies is illustrated. The possibility of apical cell membrane damage caused by microelectrodes is critically examined and tested using the polyene antibiotic Nystatin. Using data from transepithelial and microelectrode experiments, a model for net Na+ transport across the bladder is proposed and then critically analyzed. The possible clinical implications of the in vitro experiments are briefly discussed.

Dietary Genistein Inactivates Rat Thyroid Peroxidase in Vivo without an Apparent Hypothyroid Effect

2000 ◽  
Vol 168 (3) ◽  
pp. 244-252 ◽  
Author(s):  
Hebron C. Chang ◽  
Daniel R. Doerge
Keyword(s):  
Thyroid Peroxidase ◽  
Rat Thyroid

Cell and luminal pH in the proximal tubule of Necturus kidney

1984 ◽  
Vol 247 (6) ◽  
pp. F932-F938 ◽  
Author(s):  
G. Planelles ◽  
A. Kurkdjian ◽  
T. Anagnostopoulos
Keyword(s):  
Proximal Tubule ◽  
Apical Cell ◽  
Proximal Tubule Cell ◽  
Peritubular Capillary ◽  
Initial Portion ◽  
Apical Cell Membrane ◽  
Blood Ph ◽  
Cell Ph ◽  
Luminal Ph

Double-barreled, selective microelectrodes filled with liquid ion exchanger were used to determine proximal tubule cell pH (pHcell), luminal pH (pHlum), and peritubular capillary blood pH (pHbl.pt) in Necturus kidney in vivo. The average pHbl.pt of 16 animals was 7.64 +/- 0.3; pHcell was 7.36 +/- 0.02 (n = 50), and pHlum was 7.50 +/- 0.05 (n = 16). Because of the variability in pHbl.pt from one animal to another, we studied the blood/cell/lumen pH differences. We sequentially measured with a single microelectrode pHcell and pHlum, and then pHbl.pt in an adjacent peritubular capillary. In 25 such paired determinations, the average pHbl.pt - pHcell difference was 0.28 +/- 0.03, cell acid, and the pHbl.pt - pHlum difference was 0.14 +/- 0.02, lumen acid. The pHcell in this series was significantly more acid than the pHlum (by 0.14 +/- 0.02), but in a few instances the pH gradient across the apical cell membrane was inversed. All measurements were performed in the initial portion of the proximal tubule. We conclude that 1) proximal cell pH is acid with regard to peritubular blood pH, 2) the proximal tubule of Necturus kidney is capable of establishing a small transepithelial pH difference (lumen acid), and 3) pHcell is generally more acid then pHlum.

Survival and Function of Bioengineered Cardiac Grafts

Circulation ◽  
1999 ◽  
Vol 100 (suppl_2) ◽  
Author(s):  
Ren-Ke Li ◽  
Zhi-Qiang Jia ◽  
Richard D. Weisel ◽  
Donald A. G. Mickle ◽  
Angel Choi ◽  
...  
Keyword(s):  
Tissue Culture ◽  
Subcutaneous Tissue ◽  
Scar Tissue ◽  
Myocardial Scar ◽  
Fetal Rat ◽  
Myocardial Scar Tissue ◽  
And Function ◽  
Cardiac Graft

Introduction —Patients with congenital heart disease frequently require graft material for repair of cardiac defects. However, currently available grafts lack growth potential and are noncontractile and thrombogenic. We have developed a viable cardiac graft that contracts spontaneously in tissue culture by seeding cells derived from fetal rat ventricular muscle into a biodegradable material. We report our investigations of the in vitro and in vivo survival and function of this bioengineered cardiac graft. Methods and Results —A cardiomyocyte-enriched cell inoculum derived from fetal rat ventricular muscle was seeded into a piece of Gelfoam (Upjohn, Ontario, Canada), a biodegradable gelatin mesh, to form the graft. For in vitro studies, growth patterns of the cells within the graft were evaluated by constructing growth curves and by histologic examination; in in vivo studies, the graft was cultured for 7 days and then implanted either into the subcutaneous tissue of adult rat legs or onto myocardial scar tissue in a cryoinjured rat heart. Five weeks later, the graft was studied histologically. The inoculated cells attached to the gelatin mesh and grew in 3 dimensions in tissue culture, forming a beating cardiac graft. In both the subcutaneous tissue and the myocardial scar, blood vessels grew into the graft from the surrounding tissue. The graft implanted into the subcutaneous tissue contracted regularly and spontaneously. When implanted onto myocardial scar tissue, the cells within the graft survived and formed junctions with the recipient heart cells. Conclusions —Fetal rat ventricular cells can grow 3-dimensionally in a gelatin mesh. The cells in the graft formed cardiac tissue and survived and contracted spontaneously both in tissue culture and after subcutaneous implantation. Future versions of this bioengineered cardiac graft may eventually be used to repair cardiac defects.

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.

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.

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

Effect of serum thyrotropin levels on the concentration of messenger RNA for thyroid peroxidase in the rat

1992 ◽  
Vol 126 (5) ◽  
pp. 460-466 ◽  
Author(s):  
Ronald P Magnusson ◽  
Bo Yu ◽  
Veronica Brennan
Keyword(s):  
Messenger Rna ◽  
Thyroid Peroxidase ◽  
Mrna Levels ◽  
Hypophysectomized Rats ◽  
Steady State Levels ◽  
Low Levels ◽  
Rat Thyroid ◽  
Serum Tsh ◽  
Bovine Tsh

The effect of serum TSH on rat thyroid peroxidase mRNA levels was studied in order to investigate the regulation of thyroid peroxidase gene expression in vivo. A nearly full-length rat thyroid peroxidase cDNA clone was isolated from a bacteriophage cDNA library synthesized using poly A+ RNA isolated from the thyroids of propylthiouracil-treated rats. cDNA probes derived from this clone were used to study rat thyroid peroxidase mRNA levels in response to the level of serum TSH. Two major rat thyroid peroxidase mRNA bands were detected on Northern blots of total cellular RNA (at 3.2 kb and at 3.7kb). Injection of thyroxine, which lowered the levels of serum TSH, also lowered the steady-state levels of both rat thyroid peroxidase mRNAs, whereas treatment with methimazole, which increased serum TSH, increased both rat thyroid peroxidase mRNA levels. In hypophysectomized rats 10 days postoperative, very low levels of thyroid peroxidase mRNA were observed. Injection of bovine TSH (1 IU/day) increased rat thyroid peroxidase mRNA expression, preferentially in the 3.2 kb band. These results clearly demonstrate that TSH regulates rat thyroid peroxidase mRNA levels in vivo.

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