The thyroid gland of the woodchuck,Marmota monax: A morphological study of seasonal variations in the follicular cells

1977 ◽  
Vol 187 (4) ◽  
pp. 495-513 ◽  
Author(s):  
P. P. Krupp ◽  
R. A. Young ◽  
R. Frink
Keyword(s):  
Thyroid Gland ◽  
Seasonal Variations ◽  
Morphological Study ◽  
Follicular Cells ◽  
Marmota Monax

The secretion of proteins in vitro from Xenopus oocytes and their accessory cells: a biochemical and morphological study

Development ◽  
1981 ◽  
Vol 61 (1) ◽  
pp. 367-383
Author(s):  
T. J. Mohun ◽  
C. D. Lane ◽  
A. Colman ◽  
C. C. Wylie
Keyword(s):  
Gel Electrophoresis ◽  
Messenger Rna ◽  
Morphological Study ◽  
Xenopus Oocytes ◽  
Secretory Proteins ◽  
Xenopus Laevis Oocytes ◽  
Follicular Cells ◽  
Two Dimensional Gel Electrophoresis ◽  
Accessory Cells

Protein secretion by Xenopus laevis oocytes and their surrounding follicular cells in vitro has been investigated using two-dimensional gel electrophoresis. Viable oocytes, devoid of follicle layers, were prepared by treatment with collagenase; they retain in full their capacity to synthesize, sequester and export secretory proteins following microinjection with heterologous messenger RNA. Both RNA-injected and normal cells export a large number of endogenous oocyte proteins and, as with heterologous secretory translation products, these proteins are found within the oocyte in a vesicle fraction. Electron microscopy indicates that secretion involves exocytotic release of cortical vesicle contents. The follicular cells themselves also seem to contribute a number of proteins to the incubation medium surrounding isolated oocytes, but the presence of follicle layers is not required for the export of endogenous oocyte proteins.

The Thyroid Gland: Physiology and Pathophysiology

2000 ◽  
Vol 19 (8) ◽  
pp. 11-26 ◽  
Author(s):  
Denise Kirsten
Keyword(s):  
Thyroid Gland ◽  
Thyroid Hormones ◽  
Laboratory Tests ◽  
Clinical Manifestations ◽  
Thyroid Stimulating Hormone ◽  
The Body ◽  
Premature Delivery ◽  
Follicular Cells ◽  
Metabolic Hormones ◽  
Radiologic Findings

The thyroid gland contains many follicular cells that store the thyroid hormones within the thyroglobulin molecule until they are needed by the body. The thyroid hormones, often referred to as the major metabolic hormones, affect virtually every cell in the body. Synthesis and secretion of the thyroid hormones depend on the presence of iodine and tyrosine as well as maturation of the hypothalamic-pituitary-thyroid system. Interruption of this development, as occurs with premature delivery, results in inadequate production of thyroid-stimulating hormone and thyroxine, leading to a variety of physiologic conditions. Pathologic conditions occur in the presence of insufficient thyroid production or a defect in the thyroid gland. Laboratory tests are important in diagnosing conditions of the thyroid gland. A thorough history in combination with clinical manifestations and radiologic findings are also useful in diagnosing specific thyroid conditions. Nurses play an important role in identifying and managing thyroid disorders and in providing supportive care to infants and their families.

ROLE OF THE THYROID GLAND IN REGULATION OF METABOLIC RATE IN AN AIR-BREATHING SILUROID FISH, HETEROPNEUSTES FOSSILIS (BLOCH)

1976 ◽  
Vol 69 (3) ◽  
pp. 421-425 ◽  
Author(s):  
B. N. PANDEY ◽  
J. S. D. MUNSHI
Keyword(s):  
Oxygen Consumption ◽  
Thyroid Gland ◽  
Metabolic Rate ◽  
Seasonal Variations ◽  
Heteropneustes Fossilis ◽  
Cyclic Activity ◽  
Experimental Conditions ◽  
Probable Role ◽  
Made In

SUMMARY Studies on cyclic activity of the thyroid and seasonal variations in oxygen consumption (V̇o2) under experimental conditions in which surfacing was either allowed or prevented were made in H. fossilis to try to establish a relationship between these measures and to ascertain the possible role of the thyroid in the regulation of metabolic rate. A good correlation was found between the activity of the thyroid and V̇o2 in this species. This finding was further confirmed by the administration of l-thyroxine or thiouracil to this fish. The thyroxine-and thiouracil-treated animals showed significantly higher (P < 0·05) and lower (P < 0·01) rates of V̇o2 respectively, thus indicating the probable role of the thyroid in the regulation of metabolic rate.

scholarly journals Thyroid hormone transporters

2005 ◽  
Vol 33 (1) ◽  
pp. 228-232 ◽  
Author(s):  
E.C.H. Friesema ◽  
J. Jansen ◽  
T.J Visser
Keyword(s):  
Biological Activity ◽  
Thyroid Hormone ◽  
Thyroid Gland ◽  
Cell Membrane ◽  
Human Chromosome ◽  
Elevated Serum ◽  
Psychomotor Retardation ◽  
Follicular Cells ◽  
Serum T3 ◽  
T3 Receptors

Thyroid hormone is important for development of various tissues, in particular brain, and for regulation of metabolic processes throughout life. The follicular cells of the thyroid gland produce predominantly T4 (thyroxine), but the biological activity of thyroid hormone is largely exerted by T3 (3,3′,5-tri-iodothyronine). The deiodinases involved in T4-to-T3 conversion or T4 and T3 degradation, as well as the T3 receptors, are located intracellularly. Therefore the action and metabolism of thyroid hormone require transport of iodothyronines across the cell membrane via specific transporters. Recently, a number of transporters capable of cellular uptake of iodothyronines have been identified. The most specific transporters identified so far are OATP1C1 and MCT8, which appear to be involved in T4 transport across the blood–brain barrier, and in T3 transport into brain neurons, respectively. The MCT8 gene is located on human chromosome Xq13, and mutations in MCT8 are associated with X-linked severe psychomotor retardation and elevated serum T3 levels.

scholarly journals Immunocytochemical localization of cathepsins B, H, L, and T4 in follicular cells of rat thyroid gland.

1989 ◽  
Vol 37 (5) ◽  
pp. 691-696 ◽  
Author(s):  
Y Uchiyama ◽  
T Watanabe ◽  
M Watanabe ◽  
Y Ishii ◽  
H Matsuba ◽  
...  
Keyword(s):  
Thyroid Gland ◽  
Thyroid Tissue ◽  
Double Immunostaining ◽  
Follicular Cells ◽  
Thin Sections ◽  
Dense Granules ◽  
Dense Bodies ◽  
Rat Thyroid ◽  
Monospecific Antibodies ◽  
Rat Thyroid Gland

To localize cathepsins B, H, and L in follicular cells of rat thyroid gland, we applied immunocytochemistry to the thyroid tissue using their respective monospecific antibodies. On serial semi-thin sections, cathepsins B, H, and L were localized in granules of various sizes located throughout the cytoplasm, whereas T4 was detected in larger granules located in the apical and supranuclear regions. By electron microscopy, cathepsins B, H, and L were localized in large less-dense granules (so-called colloid droplets) and in dense bodies of various sizes, whereas T4 was localized more intensely in large less-dense granules than in smaller dense bodies. By double immunostaining using an immunogold method, cathepsins H and B or L were co-localized in the same cytoplasmic granules. Moreover, immunoblotting demonstrated that proteins similar to cathepsins B, H, and L in the liver are present in the thyroid gland. These results suggest that cathepsins B, H, and L participate not only in degradation of thyroglobulin but in maturation of thyroid hormones, although it remains unknown whether all of them participate in the maturation process.

Histometrical Changes in the Thyroid Gland of Chabro Chicken Reared during Summer and Winter Seasons

2020 ◽  
Author(s):  
Amit Singh Vishen ◽  
Varsha Gupta ◽  
S.P. Singh ◽  
Abhinov Verma ◽  
Rakesh Kumar Gupta ◽  
...  
Keyword(s):  
Thyroid Gland ◽  
Seasonal Changes ◽  
Squamous Epithelium ◽  
Poultry Farm ◽  
Follicular Cells ◽  
Climatic Variations ◽  
Reticular Fibers ◽  
Poultry Birds ◽  
The Tropics ◽  
Apparently Healthy

Background: Chabro is a strain of poultry birds especially designed for backyard farming and is more adoptive to climatic variations in the tropics. The thyroid gland plays an important role in controlling basal metabolic rate. The histoarchitectural changes of the gland in association with seasonal changes has not been studied so far in Chabro. The present study describes the season related variations in the histometry of thyroid gland.Methods: Micrometrical studies were conducted on thyroid gland of eight to ten weeks old 24 apparently healthy Chabro chickens procured from Poultry Farm, DUVASU, Mathura after approval of CPCSEA. For this study the chickens were divided into two groups consist of 12 chickens in each group reared in summer and winter seasons.Result: Histologically, the thyroid gland was composed of stroma and parenchyma. The capsule had outer thick adipose and inner thin fibrous layers. The follicles were filled with colloid produced by the follicular cells. The percentage of small follicles was more followed by medium and large follicles. The follicles were lined by simple squamous epithelium in summer and cuboidal epithelial cells in winter. All micrometrical parameters, amount of reticular fibers, percentage of large and active follicles were higher in winter.

Thyrotrophin-releasing hormone (TRH) and hormone secretion from the follicular and C-cells of perfused dog thyroid lobes

1985 ◽  
Vol 109 (4) ◽  
pp. 499-504 ◽  
Author(s):  
E. Iversen ◽  
P. Laurberg
Keyword(s):  
Thyroid Hormone ◽  
Thyroid Gland ◽  
Hormone Secretion ◽  
Inhibitory Effect ◽  
C Cells ◽  
Follicular Cells ◽  
Thyrotrophin Releasing Hormone ◽  
Releasing Hormone ◽  
Direct Inhibitory Effect ◽  
Thyroid Secretion

Abstract. Recently we found small amounts of TRH immunoreactivity in the thyroid gland of dogs and pigs. In the present study we investigated if exogenous TRH influences the release of T4, T3 and cAMP from the follicular cells, and calcitonin and somatostatin from the C-cells of perfused dog thyroid lobes. 10−5 mol/l TRH inhibited the TSH induced iodothyronine and cAMP release from the thyroid while 10−8 mol/l TRH had no effect. The relative proportions of T4 and T3 in thyroid secretion were not altered by TRH infusion. TRH did not influence the basal or the Ca++ induced release of somatostatin and calcitonin. Hence TRH has a direct inhibitory effect on the hormone secretion from thyroidal follicular cells. This opens the possibility that TRH in the thyroid participate in the regulation of thyroid hormone secretion. Even though the concentration of TRH found to be effective is high our results may indicate that TRH in the thyroid participates in the regulation of thyroid hormone secretion as an antagonist to TSH.

Sign in / Sign up

Export Citation Format

Share Document