Thyroid growth and its relationship to metamorphosis in Rana temporaria

Development ◽  
1966 ◽  
Vol 16 (3) ◽  
pp. 487-496
Author(s):  
Harold Fox
Keyword(s):  
Thyroid Gland ◽  
Growth And Development ◽  
Maximum Rate ◽  
Cellular Proliferation ◽  
Rana Temporaria ◽  
Thyroid Cells ◽  
Metamorphic Climax

In a previous work on pronephric degeneration, larvae of Rana temporaria from practically the whole range of the metamorphic cycle were studied (Fox, 1962). Metamorphosis in anurans is dependent upon the presence of a functional thyroid gland (Kollros, 1951; Lynn & Wachowski, 1951; Etkin, 1964), and the same specimens have now been used to investigate thyroid growth and development quantitatively and qualitatively, especially in relation to those major events which occur at the metamorphic climax between stages 49 and 54 (Cambar & Marrot, 1954). It will be shown that in larvae from 16 mm long (stage 41; see Fox, 1962) until practically the end of the climax (stage > 53), thyroid cells are of stable volume (about 700 μ3), and thyroid enlargement is by cellular proliferation and vesicular expansion. The maximum rate of thyroid growth occurs between 16 mm and 28 mm (stages 41–45).

DYNAMIC MORPHOLOGICAL CHANGES IN THE THYROID GLAND ASSOCIATED WITH DEPLETION OF DEUTERIUM BODY CONTENT

2021 ◽  
Author(s):  
Ekaterina Timokhina ◽  
◽  
Nataliya Yaglova ◽  
Sergey Obernikhin ◽  
Valentin Yaglov ◽  
...  
Keyword(s):  
Thyroid Gland ◽  
Morphological Changes ◽  
Hormone Secretion ◽  
Deuterium Content ◽  
Thyroid Cells

Dynamics of morphological changes in the thyroid gland of mice, consuming water with lower deuterium content, was studied. Primary changes in structure were indicative of more active hormone secretion. Later morphological signs of inhibited hormone secretion were found. The findings demonstrate sensitivity of thyroid cells to shifts in deuterium body con-tent.

Connexin-32 acts as a downregulator of growth of thyroid gland

2008 ◽  
Vol 294 (2) ◽  
pp. E291-E299 ◽  
Author(s):  
Gaëlle Prost ◽  
Françoise Bernier-Valentin ◽  
Yvonne Munari-Silem ◽  
Samia Selmi-Ruby ◽  
Bernard Rousset
Keyword(s):  
Thyroid Gland ◽  
Sodium Perchlorate ◽  
Growth Potential ◽  
Thyroid Cell ◽  
Wild Type ◽  
Thyroid Cells ◽  
Growth Increase ◽  
Thyroid Hyperplasia ◽  
Regulatory Functions

Thyroid epithelial cells communicate through gap junctions formed from connexin (Cx)32, Cx43, and Cx26. We previously reported that reexpression of Cx32 in “gap junction-deficient” FRTL-5 and FRT thyroid cell lines induces a reduction of cell proliferation rate and an activation of expression of cell differentiation. The present study aimed at determining whether Cx32 could exert similar regulatory functions in vivo. We investigated morphological and functional characteristics of thyroid gland of Cx32-deficient mice (Cx32-KO), mice overexpressing Cx32 selectively in the thyroid (Cx32-T+), and Cx32-KO mice with a thyroid-selective Cx32 complementation obtained by crossing Cx32-KO and Cx32-T+ mice. In basal conditions, Cx32-KO mice did not present any detectable thyroid alteration, whereas Cx32-T+ mice showed a thyroid hypoplasia (20% reduction) associated with a slight increase in thyroid functional activity. Under thyrotropin stimulation (following sodium perchlorate treatment), Cx32-KO mice developed a larger goiter (≤65% increase) than wild-type littermates, whereas Cx32-T+ mice exhibited the same thyroid hyperplasia as wild-type mice. Restoration of Cx32 expression in the thyroid of Cx32-KO mice abrogated the thyroid growth increase related to Cx32 deficiency. All together, these data show that Cx32 acts as a downregulator of growth of thyroid gland; an excess of Cx32 limits growth of thyroid cells in the basal state, whereas a lack of Cx32 confers an additional growth potential to TSH-stimulated thyroid cells.

scholarly journals A PURE STRAIN OF THYROID CELLS AND ITS CHARACTERISTICS

1925 ◽  
Vol 41 (3) ◽  
pp. 337-346 ◽  
Author(s):  
Albert H. Ebeling
Keyword(s):  
Thyroid Gland ◽  
Cell Multiplication ◽  
Pure Strain ◽  
Thyroid Cells ◽  
Glandular Structure ◽  
Active Condition ◽  
Thyroid Epithelium

1. A pure strain of thyroid epithelium was isolated and maintained in active condition for 7 months. At the end of the experiment, the rate of cell multiplication was as great as at its beginning. 2. The thyroid cells grew at the surface of the coagulum as pavement epithelium, and within the coagulum as a glandular structure. 3. The cells did not dedifferentiate, and the lumen of the acini in cultures from a strain over 4 months old contained colloid secretion similar morphologically to that from a freshly extirpated thyroid gland.

scholarly journals The effects of vitamins and trace minerals on chronic autoimmune thyroiditis

2014 ◽  
Vol 83 (2) ◽  
pp. 167-172
Author(s):  
Małgorzata Włochal ◽  
Marcin A. Kucharski ◽  
Marian Grzymisławski
Keyword(s):  
Thyroid Gland ◽  
Hashimoto’S Thyroiditis ◽  
Essential Element ◽  
Hashimoto Thyroiditis ◽  
Hashimoto's Thyroiditis ◽  
Thyroid Peroxidase ◽  
Chronic Lymphocytic Thyroiditis ◽  
Thyroid Cells ◽  
Thyroglobulin Antibodies ◽  
Chronic Autoimmune Thyroiditis

Hashimoto’s thyroiditis (HT), also known as chronic lymphocytic thyroiditis is one of the most frequent types of inflammation of the thyroid gland. The prevalence of the overt HT is about 2% but it is believed that Hashimoto thyroiditis is more frequent than expected. Hashimoto’s thyroiditis is characterized by dysfunction of the immune system, which leads to impaired tolerance of own tissues and increased production of autoantibodies against the thyroid cells. Thyroid peroxidase antibodies (anti-TPO), thyroglobulin antibodies (anti-Tg) and/or TSH receptors antibodies are the principal markers of the disease. The essential element of the treatment of HT is the supplementation of L-thyroxine. In Hashimoto’s disease, like in many other autoimmune diseases, researchers attempted to support pharmacological treatment by adequate nutrition. The aim of this paper was to review the existing literature on the levels of antioxidants (vitamin A, C, E, selenium, zinc) and vitamin D in patients with HT, as well as the influence of the nutritional supplementation of the above mentioned elements on the metabolism of the thyroid gland hormones and the level of anti-thyroid peroxidase (anti-TPO) antibodies.

scholarly journals Placental changes in hypertensive pregnancy: a comparison with normotensive pregnancy

2018 ◽  
Vol 7 (9) ◽  
pp. 3808
Author(s):  
Jashan Chhatwal ◽  
Dev Nanda Chaudhary ◽  
Neena Chauhan
Keyword(s):  
Pregnant Women ◽  
Growth And Development ◽  
Cellular Proliferation ◽  
Gestational Hypertension ◽  
Control Group ◽  
Hypertensive Disorder ◽  
Singleton Pregnancy ◽  
Chi Square ◽  
Histological Changes ◽  
Hypertensive Pregnancy

Background: Hypertensive pregnancy may be responsible for vascular damage, enhanced systemic inflammation and insulin resistance in the placenta as oxygen and nutrient transfer is impaired and oxidative stress is generated affecting the placental growth and development. Placental growth pattern in hypertensive pregnancies shows a variable pattern owing to placental insufficiency. Present study was done to investigate the morphological and histological changes in placenta in hypertensive pregnancy.Methods: A total of 42 pregnant women with hypertensive disorder with gestational age 28-42 weeks and singleton pregnancy were enrolled as cases in the study. A total of 42 matched normotensive pregnant women were enrolled as controls. All the women were followed up till delivery. At delivery, placental specimen were collected and assessed for morphological, morphometric and histological changes. Findings were compared with normotensives. Data was compared using Independent sample’s ‘t’-test and Chi-square test.Results: Mean age of cases was 27.60±4.37 years, majority were gravida 1/2 (66.7%), 45.2% had moderate to severe edema, 50% had urinary albumin levels >100 mg/dl. A total of 8 (19.0%) had gestational hypertension, 16 (38.1%) had preeclampsia, 10 (23.8%) had severe preeclampsia and 8 (19.0%) had eclampsia. Mean placental weight and diameter of cases was significantly higher than that of control group. Mean placental thickness was also higher but difference was not significant statistically. Calcification, infarction and hematoma were seen in 45.2%, 16.7% and 11.9% of cases as compared to 28.6%, 4.97% and 0% of controls. Histologically, syncytial knots, cytotrophoblastic cellular proliferation, hyalinized area, proliferation of medium sized blood vessels, stromal fibrosis and fibrinoid necrosis in significantly higher proportion of cass as compared to controls (p<0.05). Mean fetoplacental ratio was 5.01±0.99 and 5.24±0.61 in controls (p=0.195).Conclusions: Hypertension during pregnancy affects the placental growth and development.

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