THE EFFECT OF IODINE DEFICIENCY AND SUPPRESSION OF TSH SECRETION ON RADIOIODINE LABELLED THYROXINE AND TRIIODOTHYRONINE IN THE THYROID OF RATS

1971 ◽  
Vol 68 (2) ◽  
pp. 377-386 ◽  
Author(s):  
D. Emrich ◽  
A. v. zur Mühlen ◽  
G. Burmeister ◽  
H.-D. Zimmermann ◽  
R. Beckmann
Keyword(s):  
Heart Rate ◽  
Thyroid Gland ◽  
Iodine Deficiency ◽  
Iodine Concentration ◽  
Conversion Ratio ◽  
The Other ◽  
Normal Range ◽  
Tsh Secretion ◽  
Tsh Stimulation ◽  
Stimulation Of

ABSTRACT It has been suggested that TSH stimulation of the thyroid gland is accompanied by an alteration in the ratio of newly synthesized thyroxine (*T4)1)/triiodothyronine (*T3) in favour of *T3. Evidence in support of this hypothesis is provided here by the finding that suppression of TSH secretion in rats alters this ratio in the other direction, i. e. in favour of *T4. Thus, endogenous TSH stimulation was increased for 4 weeks by iodine deficiency. Its suppression was performed by the administration of T3, using a dose of 0.05-0.25 μg/100 g body weight which was injected subcutaneously every 12 hours for three days. The effect of TSH stimulation and suppression could be assessed from the following parameters: thyroid weight and histology, thyroid 131I uptake, 131I conversion ratio, hormonal iodine concentration, and TSH level in the plasma. After iodine deficiency the ratio of *T4/*T3 in the thyroid gland changed in favour of *T3. This may compensate for the iodine deficiency, since the oxygen consumption and the heart rate of the animals remained in the normal range. After suppression the ratio of *T4/*T3 changed in the opposite direction, i. e. in favour of *T4. The extent of the suppression of *T4 and *T3 was dependent on the suppression dose used.

scholarly journals HYPOTHYROIDISM AND GOITER IN A YOUNG MALE WITH SUSPECTED DIETARY IODINE DEFICIENCY FOLLOWED BY THYROTOXICOSIS AFTER IODINE SUPPLEMENTATION

2020 ◽  
Vol 6 (1) ◽  
pp. e19-e22
Author(s):  
Itivrita Goyal ◽  
Manu Raj Pandey ◽  
Rajeev Sharma
Keyword(s):  
Thyroid Gland ◽  
Thyroid Function ◽  
Iodine Deficiency ◽  
Urinary Iodine ◽  
Young Male ◽  
Free Thyroxine ◽  
Thyroid Function Tests ◽  
Normal Range ◽  
Iodine Supplementation ◽  
Function Tests

Objective: Iodine deficiency disorders (IDDs) remain a major public health concern in most parts of the world but are extremely rare in North America. We describe a case of goiter in a young male with dietary history and findings suggestive of IDD. Methods: Laboratory and imaging procedures including thyroid function tests, autoantibodies, urine iodine, thyroid ultrasound, and radioactive iodine (RAI) uptake scan were performed. Results: On initial presentation, thyroid-stimulating hormone (TSH) was 24.4 mIU/L (normal range is 0.4 to 5.0 mIU/L), free thyroxine was <0.4 ng/dL (normal range is 0.8 to 1.8 ng/dL), and thyroid peroxidase antibody was positive at 43 IU/mL (normal range is <35 IU/mL). He reported consuming strawberries and peanut butter sandwiches with no intake of dairy or seafood due to gastrointestinal issues (abdominal pain, bloating, and nausea). Physical exam revealed a diffusely enlarged, palpable thyroid gland (grade II goiter). Ultrasound of the neck showed an enlarged thyroid gland with no nodules. RAI uptake scan showed diffuse increased uptake (91%). Given his poor diet, a 24-hour urinary iodine excretion test was ordered which was suggestive of very low iodine intake. He was started on multivitamins with 150 μg of iodine daily. On follow up, clinical exam showed grade I goiter and TSH had normalized to 0.7 mIU/L and free thyroxine was 1.2 ng/dL. He continued on iodine supplementation and tolerated iodine-rich foods. Six months later, thyroid function tests showed hyperthyroidism with TSH of <0.002 ng/dL and free thyroxine was elevated to 2.8 ng/dL. Iodine supplements were stopped. Conclusion: Hypothyroidism and goiter due to IDD should be suspected in the setting of poor dietary intake. IDDs can be rapidly diagnosed in a patient on a restricted diet with multiple urinary iodine determinations and RAI study. Regular thyroid labs should be done to monitor for hyperthyroidism that can develop after iodine supplementation.

scholarly journals THE INFLUENCE OF THE AUTONOMIC NERVOUS SYSTEM ON THE FUNCTION OF THE THYROID GLAND

1925 ◽  
Vol 42 (2) ◽  
pp. 179-191 ◽  
Author(s):  
J. Hamilton Crawford ◽  
J. N. J. Hartley
Keyword(s):  
Nervous System ◽  
Autonomic Nervous System ◽  
Thyroid Gland ◽  
The Other ◽  
Histological Structure ◽  
Histological Changes ◽  
Microscopic Appearance ◽  
Marked Individual ◽  
Cervical Sympathetic ◽  
Stimulation Of

1. There is a marked individual variation in the histological structure of the thyroid gland of rabbits examined at the same season under standard conditions. Although the microscopic appearance varies in different rabbits, the structure of the two lobes in the same animal does not differ. The variations are seen principally in the size and shape of the vesicles and in the quantity and character of the colloid. 2. With one lobe as a control no histological changes in the other lobe have been observed following section or stimulation of either the cervical sympathetic or the vagus and its branches.

Effects of caffeine on energy metabolism, heart rate, and methylxanthine metabolism in lean and obese women

1995 ◽  
Vol 269 (4) ◽  
pp. E671-E678 ◽  
Author(s):  
D. Bracco ◽  
J. M. Ferrarra ◽  
M. J. Arnaud ◽  
E. Jequier ◽  
Y. Schutz
Keyword(s):  
Heart Rate ◽  
Energy Metabolism ◽  
Lipid Oxidation ◽  
Substrate Oxidation ◽  
The Other ◽  
Obese Women ◽  
Concomitant Increase ◽  
Decaffeinated Coffee ◽  
Caffeinated Coffee ◽  
Stimulation Of

The magnitude of coffee-induced thermogenesis and the influence of coffee ingestion on substrate oxidation were investigated in 10 lean and 10 obese women, over two 24-h periods in a respiratory chamber. On one occasion the subjects consumed caffeinated coffee and on the other occasion, decaffeinated coffee. The magnitude of thermogenesis was smaller in obese (4.9 +/- 2.0%) than in lean subjects (7.6 +/- 1.3%). The thermogeneic response to caffeine was prolonged during the night in lean women only. The coffee-induced stimulation of energy expenditure was mediated by a concomitant increase in lipid and carbohydrate oxidation. During the next day, in postabsorptive basal conditions, the thermogenic effect of coffee had vanished, but a significant increase in lipid oxidation was observed in both groups. The magnitude of this effect was, however, blunted in obese women (lipid oxidation increased by 29 and 10% in lean and obese women, respectively). Caffeine increased urinary epinephrine excretion. Whereas urinary caffeine excretion was similar in both groups, obese women excreted more theobromine, theophylline, and paraxanthine than lean women. Despite the high levels of urinary methylxanthine excretion, thermogenesis and lipid oxidation were less stimulated in obese than in lean subjects.

NON-TOXIC GOITRE

1974 ◽  
Vol 76 (1) ◽  
pp. 74-82 ◽  
Author(s):  
Hans Agerbæk
Keyword(s):  
Iodine Deficiency ◽  
Thyroid Tissue ◽  
Iodine Concentration ◽  
Normal Range ◽  
Normal Thyroid ◽  
Thyroid Glands ◽  
Adenomatous Tissue ◽  
Nodular Tissue ◽  
Inorganic Iodine ◽  
Deficient Group

ABSTRACT Among 29 patients operated on for non-toxic goitre 17 had a plasmaiodine concentration and thyroid clearance within the normal range for the region while 12 patients were iodine deficient in comparison to the former group. Extensive investigations of the 29 patients were performed including chromatography of the serum, urine and thyroid-gland digest and measurement of the iodine concentration and content of the goitrous tissue. No qualitative differences were found between the groups, on the contrary, a continuum existed, findings being related to the degree of iodine deficiency. Thus, the group with a low plasma inorganic iodine (PII) showed the largest goitres, lowest thyroid tissue iodine concentration and highest [125I] MIT/DIT and [125I] T3/T4 thyroid-tissue ratio. In the group with a "normal" PII concentration, iodoamino acid distribution in the para-adenomatous tissue was similar to that of "normal" thyroid glands in the present region, whereas nodular tissue compared with the goitrous tissue of the most iodine deficient group. Thus, only quantitative differences were found between the groups, and it is concluded that the goitres of both groups were due to iodine deficiency.

Thyroglobulin assay in the follow-up of patients with differentiated thyroid carcinomas: comparison of its value in patients with or without normal residual tissue

1981 ◽  
Vol 98 (2) ◽  
pp. 215-221 ◽  
Author(s):  
M. Schlumberger ◽  
P. Fragu ◽  
C. Parmentier ◽  
M. Tubiana
Keyword(s):  
Replacement Therapy ◽  
Lung Metastases ◽  
Thyroid Tissue ◽  
The Other ◽  
Normal Range ◽  
Neoplastic Tissue ◽  
Serum Thyroglobulin ◽  
Thyroid Carcinomas ◽  
Tsh Stimulation

Abstract. The usefulness of serum thyroglobulin (Tg) assay in the follow-up of differentiated thyroid carcinomas has been evaluated in 109 subjects divided into two groups. Group 1 included 64 patients who had undergone total thyroid ablation. In 40 of the 41 patients in complete remission serum Tg was undetectable during replacement therapy (TSH below 5 μU/ml). In 18 out of the 40 patients serum TG was detectable following endogenous TSH stimulation. As 83% of these patients had ectopic uptake prior to the last radioiodine treatment, this release of Tg under TSH stimulation suggests the persistence of occult neoplastic tissue. Of the other 23 patients, 20 had bone or lung metastases and 3 patients had lymph node recurrences: in all these patients, serum Tg was detectable during replacement therapy and increased after TSH stimulation. Group 2 included 45 patients in whom normal residual thyroid tissue was present at the time of the investigation. Of these, 35 patients were in apparent remission and 19 of them had detectable Tg level within the normal range. The other 10 patients had detectable metastases and in 4 of these the Tg level was also within the normal range. Thus, no conclusion can be drawn from a normal Tg level in the presence of residual thyroid tissue. Bovine TSH stimulation did not improve significantly the diagnostic value of Tg assay in this group of patients.

Thrombotic Thrombocytopenic Purpura: Mechanism for Effectiveness of Plasmapheresis

1979 ◽  
Author(s):  
J. G. Kelton ◽  
P. B. Neame ◽  
I. Walker ◽  
A. G. Turpie ◽  
J. McBride ◽  
...  
Keyword(s):  
Platelet Count ◽  
Thrombotic Thrombocytopenic Purpura ◽  
The Other ◽  
Unknown Etiology ◽  
Normal Range ◽  
Antiplatelet Antibody ◽  
Thrombocytopenic Purpura ◽  
Serious Illness ◽  
Normal Platelet ◽  
Very High

Thrombotic thrombocytopenic purpura (TTP) is a rare but serious illness of unknown etiology. Treatment by plasmapheresis has been reported to be effective but the mechanism for benefit is unknown. We have investigated the effect of plasmapheresis in 2 patients with TTP by quantitating platelet associated IgG (PAIgG) levels prior to and following plasmapheresis. Both patients had very high levels of PAIgG at presentation (90 and A8 fg IgG/platelet respectively, normal 0-5). in both, the PAIgG levels progressively fell to within the normal range and the platelet count rose following plasmapheresis. One patient remained in remission with normal platelet counts and PAIgG levels. The other relapsed after plasmapheresis and the PAIgG level rose prior to the fall in platelet count. Plasmapheresis was repeated and resulted in normalization of both the platelet count and PAIgG level. It is suggested that plasmapheresis removes antiplatelet antibody or immune complexes which may be of etiological importance in this illness.

DER EINFLUSS VON RESERPIN AUF DIE ANTITHYREOIDALE WIRKUNG VON KALIUMPERCHLORAT

1962 ◽  
Vol 39 (3) ◽  
pp. 423-430
Author(s):  
H. L. Krüskemper ◽  
F. J. Kessler ◽  
E. Steinkrüger
Keyword(s):  
Thyroid Gland ◽  
Male Rats ◽  
Normal Male ◽  
Tissue Respiration ◽  
List Type ◽  
Morphological Alterations ◽  
Hormone Synthesis ◽  
Stimulation Of

ABSTRACT 1. Reserpine does not inhibit the tissue respiration of liver in normal male rats (in vitro). 2. The decrease of tissue respiration of the liver with simultaneous morphological stimulation of the thyroid gland after long administration of reserpine is due to a minute inhibition of the hormone synthesis in the thyroid gland. 3. The morphological alterations of the thyroid in experimental hypothyroidism due to perchlorate can not be prevented with reserpine.

EFFECT OF ACTINOMYCIN D ON TSH-INDUCED STIMULATION OF THYROIDAL PROTEIN SYNTHESIS IN THE RAT

1974 ◽  
Vol 77 (1) ◽  
pp. 64-70 ◽  
Author(s):  
Gustav Wägar
Keyword(s):  
Protein Synthesis ◽  
Actinomycin D ◽  
The Other ◽  
Leucine Incorporation ◽  
Short Term ◽  
Other Hand ◽  
Thyroid Glands ◽  
Translational Level ◽  
Stimulation Of

ABSTRACT Whether the short-term regulation of thyroidal protein synthesis by TSH occurs at the transcriptional or the translational level was tested by measuring the effect of actinomycin D (act D) on the TSH-induced stimulation of L-14C-leucine incorporation into the thyroidal proteins of rats. TSH was injected 6 h before the rats were killed. The thyroid glands were then removed and incubated in vitro in the presence of L-14C-leucine for 2 h. The pronounced stimulation of leucine incorporation in the TSH-treated animals was depressed as compared with controls but still significant even when the animals had been pre-treated with 100 μg act D 24 and 7 h before sacrifice. On the other hand, act D strongly decreased incorporation of 3H-uridine into RNA. Short-term regulation of thyroidal protein synthesis by TSH appears to be partly but not wholly dependent on neosynthesis of RNA. Hence regulation may partly occur at the translation level of protein synthesis.

Electrical stimulation of the carotid sinus lowers arterial pressure and improves heart rate variability in l-NAME hypertensive conscious rats

2020 ◽  
Vol 43 (10) ◽  
pp. 1057-1067 ◽  
Author(s):  
Gean Domingos-Souza ◽  
Fernanda Machado Santos-Almeida ◽  
César Arruda Meschiari ◽  
Nathanne S. Ferreira ◽  
Camila A. Pereira ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Electrical Stimulation ◽  
Arterial Pressure ◽  
Carotid Sinus ◽  
Conscious Rats ◽  
Stimulation Of
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