EFFECT OF PTU ADDED TO A LOW IODINE DIET ON PEROXIDASE ACTIVITY AND OTHER PARAMETERS OF THYROID FUNCTION IN RATS

1979 ◽  
Vol 91 (3) ◽  
pp. 462-472
Author(s):  
P. Fragu ◽  
S. Ben Othman ◽  
B. M. Nataf
Keyword(s):  
Thyroid Gland ◽  
Thyroid Function ◽  
Peroxidase Activity ◽  
Rapid Change ◽  
Iodine Content ◽  
Thyroid Peroxidase ◽  
Significant Elevation ◽  
Cent Increase ◽  
Serum Tsh ◽  
Tsh Levels

ABSTRACT The evolution of peroxidase activity was followed in relation to other parameters of thyroid function in rats when PTU was added to a low iodine diet (LID). Ten days of PTU treatment brings about an equivalent increase in thyroid weight and iodide peroxidase activity at whatever time PTU was added to LID (10, 35, 54 and 80 days). It is shown that the effect of PTU treatment on thyroid weight and peroxidase activity is proportionately higher when PTU is added after 10 days of LID alone than after 80 days. The effect of various durations of PTU treatment was studied more closely when the addition began on day 10 of LID. On day 1 after addition of PTU thyroid weight increased significantly and no significant change was found in peroxidase activity. In contrast 5 days of PTU induced a significant elevation in enzymatic activity which is greater than that of thyroid weight. For a longer period of PTU treatment (10 days or more), the per cent increase of thyroid weight and peroxidase activity evolved parallely. Already on day 1 of PTU treatment very rapid change were noted on T4, T3 and TSH levels; there was a decrease in T3 level (26 ± 5.6 %), while an increase in T4 level (26.4 ± 4.7 %) and TSH level (30 ± 5 %) was observed when the iodine content was still high (about 11 μg/thyroid gland). Thereafter T3 and T4 decreased and stayed at the same level after 10 days of PTU, while TSH increased rapidly and reached a plateau between 18 and 35 days. When PTU was added to LID treatment the increase in TSH was mostly due to a decrease of T3. The per cent increase in serum TSH level is always higher than that of thyroid peroxidase activity.

RELATIONSHIP BETWEEN PEROXIDASE ACTIVITY AND SERUM TSH, T4 AND T3 LEVELS IN RATS IN THE COURSE OF IODINE DEFICIENCY

1978 ◽  
Vol 88 (3) ◽  
pp. 499-505 ◽  
Author(s):  
B. M. Nataf ◽  
P. Fragu ◽  
S. Ben Othman
Keyword(s):  
Iodine Deficiency ◽  
Peroxidase Activity ◽  
Control Diet ◽  
Early Period ◽  
Iodine Content ◽  
Thyroid Peroxidase ◽  
Wet Weight ◽  
Iodine Treatment ◽  
Serum Tsh ◽  
Tsh Levels

ABSTRACT The relationship between peroxidase activity and serum TSH, T4 and T3 levels was investigated in the course of iodine deficiency in rats. Rats were maintained either on a control diet with a relatively high iodine content (600 μg/kg of 127I), or on a low iodine diet (30 μg/kg of 127I). Twenty days after the low iodine treatment, the thyroid iodine [127I] concentration was half that of control value (647 ± 52 and 1241 ± 72 μg/g of wet weight, respectively). However, no significant changes in serum T4, T3, TSH were found at 20 days even though an early increase in peroxidase activity was observed. It was only at 35 days of iodine deficiency, when the concentration of iodine in the gland averaged 260 μg/g of wet weight that serum T4 and TSH levels started to be significantly modified. From day 35 to day 70, a significant and progressive decrease of plasma T4 concentration was observed, and it levelled off thereafter. The changes of serum T3 were much smaller than those of T4. A significant increase in serum TSH level was noted at 35 days. Thereafter TSH levels increased rapidly and progressively (205 % increase over control at 70 days and 643 % at 80 days). From day 35 until day 80 of the low iodine treatment, the thyroid peroxidase activity and the serum TSH level varied concomitantly. Our results suggest that for an iodine content between 5 and 2 μg per thyroid gland, the high cellular peroxidase activity observed could be correlated with an increase in circulating TSH, due to a decrease of T4. In contrast, in the early period of iodine deficiency, no correlation was found between peroxidase activity and serum T4, T3 and TSH levels.

scholarly journals Pregnancy outcomes are not altered by variation in thyroid function within the normal range in women free of thyroid disease

2018 ◽  
Vol 178 (2) ◽  
pp. 189-197 ◽  
Author(s):  
Flora Veltri ◽  
Pierre Kleynen ◽  
Lidia Grabczan ◽  
Alexandra Salajan ◽  
Serge Rozenberg ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Thyroid Function ◽  
Pregnancy Outcomes ◽  
Thyroid Disease ◽  
Thyroid Autoimmunity ◽  
Thyroid Peroxidase ◽  
Normal Range ◽  
Baseline Characteristics ◽  
Serum Tsh ◽  
Tsh Levels

ObjectiveIn the recently revised guidelines on the management of thyroid dysfunction during pregnancy, treatment with thyroid hormone (LT4) is not recommended in women without thyroid autoimmunity (TAI) and TSH levels in the range 2.5–4.0 mIU/L, and in a recent study in that particular group of pregnant women, more complications were observed when a treatment with LT4 was given. The objective of the study was therefore to investigate whether variation in thyroid function within the normal (non-pregnant) range in women free of thyroid disease was associated with altered pregnancy outcomes?DesignCross-sectional data analysis of 1321 pregnant women nested within an ongoing prospective collection of pregnant women’s data in a single centre in Brussels, Belgium.MethodsThyroid peroxidase antibodies (TPO-abs), thyroid-stimulating hormone (TSH), free T4 (FT4) and ferritin levels were measured and baseline characteristics were recorded. Women taking LT4, with TAI and thyroid function outside the normal non-pregnant range were excluded. Pregnancy outcomes and baseline characteristics were correlated with all TSH and FT4 levels within the normal range and compared between two groups (TSH cut-off < and ≥2.5 mIU/L).ResultsTobacco use was associated with higher serum TSH levels (OR: 1.38; CI 95%: 1.08–1.74);P = 0.009. FT4 levels were inversely correlated with age and BMI (rho = −0.096 and −0.089;P < 0.001 and 0.001 respectively) and positively correlated with ferritin levels (rho = 0.097;P < 0.001). Postpartum haemorrhage (>500 mL) was inversely associated with serum FT4 levels (OR: 0.35; CI 95%: 0.13–0.96);P = 0.040. Also 10% of women free of thyroid disease had serum TSH levels ≥2.5 mIU/L.ConclusionsVariation in thyroid function during the first trimester within the normal (non-pregnant) range in women free of thyroid disease was not associated with altered pregnancy outcomes. These results add evidence to the recommendation against LT4 treatment in pregnant women with high normal TSH levels and without TPO antibodies.

Thyroid sonomorphology, thyroid peroxidase antibodies and thyroid function

2008 ◽  
Vol 47 (05) ◽  
pp. 194-199 ◽  
Author(s):  
K. Balzer ◽  
J. Diener ◽  
K. Wegscheider ◽  
R. Vaupel ◽  
F. Grünwald ◽  
...  
Keyword(s):  
Thyroid Gland ◽  
Thyroid Function ◽  
Nodular Goiter ◽  
Thyroid Peroxidase ◽  
German Population ◽  
Blood Samples ◽  
Thyroid Peroxidase Antibodies ◽  
Thyroid Screening ◽  
Deutschland Gmbh ◽  
Serum Tsh

Summary Aim: Employees of Sanofi-Aventis Deutschland GmbH underwent thyroid screening in 2006 to assess new data about the prevalence of irregular sonomorphological pattern, elevated thyroid peroxidase antibodies (TPO AB) and thyroid function in an unselected adult German population. Participants, methods: The examination included 700 unselected employees. Blood samples were analyzed for serum TSH and TPO AB, and ultrasound of the thyroid was performed. Results: In 40.7% of the participants (n = 285) an irregular sonomorphological pattern was detected: goiter in 13.7%, nodules in 35.6%, nodular goiter in 8.6% and a hypoechogenic pattern of the thyroid gland in 20.4%. Serum TSH was increased in 3.9% and decreased in 0.6%. Elevated TPO AB values were observed in 13%. Only 1.4% (n= 10) showed elevated TPO AB combined with a TSH increase. Sonomorphological abnormalities were associated with increased TPO AB in 7.1%. Elevated TPO AB was observed significantly more often in combination with sonomorphological pathology (54.9%) than without (45.1%) (p = 0.003). Conclusions: Sonomorphological disorders are still very common in Germany and our results are comparable with previous screening examinations. Elevated TPO AB correlated significantly with the sonomorphological pattern of nodules and goiter. This may reflect an improved iodine supply or a hypertrophic stage of autoimmune thyroiditis in some cases.

scholarly journals Influence of Smoking on Thyroid Function in Japanese Subjects: Longitudinal Study for One Year of On-Off Smoking

2019 ◽  
Vol 3 (12) ◽  
pp. 2385-2396
Author(s):  
Yasuyo Nakajima ◽  
Sayaka Yamada ◽  
Ayaka Nishikido ◽  
Akiko Katano-Toki ◽  
Emi Ishida ◽  
...  
Keyword(s):  
Longitudinal Study ◽  
Thyroid Function ◽  
Smoking Status ◽  
Careful Consideration ◽  
Thyroid Peroxidase ◽  
Free T4 ◽  
Cross Sectional ◽  
Serum Tsh ◽  
Tsh Levels ◽  
Japanese Subjects

Abstract Context We previously identified factors affecting thyroid status, including sex, age, and smoking. Objective In the current study, we increased the number of subjects examined and investigated the effects of these factors, particularly smoking and the thyroid peroxidase antibody (TPO-Ab), in Japanese patients with euthyroxinemia and serum free T4 levels within the normal range. Participants A total of 12,289 subjects who underwent health checkups were analyzed in a cross-sectional and longitudinal study. Results The mean age of subjects was 50 ± 10 years (age range: 21 to 88 years). Serum TSH levels and the prevalence of positivity for TPO-Ab increased with age in Japanese subjects with euthyroxinemia. Mean serum TSH levels were significantly lower in the smoking group than in the nonsmoking group except for women older than 50 years. Serum TSH levels were significantly higher in subjects with positivity for TPO-Ab than in those with negativity at all ages and in both sexes; however, smoking did not affect free T4 levels or positivity for TPO-Ab. Among men, the rate of smokers was significantly higher in patients with subclinical hyperthyroidism (25%) than in those with subclinical hypothyroidism (10%; P < 0.05). Furthermore, the results of the longitudinal study revealed a significant decrease in serum TSH levels 1 year after the start of smoking in men (P < 0.05). Conclusion Because smoking appeared to lower serum TSH levels in Japanese subjects with euthyroxinemia, their smoking status warrants careful consideration when evaluating subclinical thyroid function.

scholarly journals SAT-437 Influence of Smoking on Thyroid Function in Japanese Subjects: Longitudinal Study for One Year of On-Off Smoking

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Yasuyo Nakajima ◽  
Sayaka Yamada ◽  
Ayaka Nishikido ◽  
Masayuki Yoshioka ◽  
Akiko Katano-Toki ◽  
...  
Keyword(s):  
Longitudinal Study ◽  
Thyroid Function ◽  
Thyroid Peroxidase ◽  
Free T4 ◽  
Serum Free ◽  
Thyroid Peroxidase Antibody ◽  
One Year ◽  
Old Men ◽  
Serum Tsh ◽  
Tsh Levels

Abstract Recent studies showed that various factors, including age, gender, race, iodine intake, obesity, the thyroid peroxidase antibody (TPO-Ab), and/or smoking, influence the thyroid status. In the present study, we analyzed and investigated the effects of these factors, particularly smoking and the thyroid peroxidase antibody (TPO-Ab) in Japanese euthyroxinemia individuals with serum free T4 level within normal range. A total of 12,289 subjects who underwent health check-ups were analyzed in a cross-sectional and longitudinal study. The mean age of subjects was 50 ± 10 years (age range: 21–88 years). Serum TSH levels and the prevalence of positivity for TPO-Ab increased with age in Japanese euthyroxinemia subjects. Mean and median serum TSH levels increased with age in smokers and non-smokers, but were significantly lower in smokers than in non-smokers among men and women in most age groups; the median 97.5th percentiles of TSH levels were 1.2 mU/liter and 2.9 mU/liter in smokers, and 1.4 mU/liter and 3.9 mU/liter in non-smokers in 31- to 40-year-old men, p&lt;0.01, and 1.4mU/liter and 4.3 mU/liter, and 1.8mU/liter and 6.2 mU/liter in 61- to 70-year-old men, p&lt;0.01. However, smoking had a negligible effect on serum TSH levels in women older than 50 years; 1.3 mU/liter in smokers and 1.6 mU/liter in non-smokers in 31- to 40-year-old women, p&lt;0.01, and 1.5 mU/liter and 1.8 mU/liter in 51- to 60-year-old women, p=0.3. Furthermore, the present study confirmed that serum free T4 levels in men progressively decreased with age, whereas no significant change was observed in women. Smoking did not affect the relationship between age and serum free T4 levels in men or women, except for men in their 20s. Serum TSH levels were significantly higher in subjects with positivity for TPO-Ab than in those with negativity at all ages and in both genders; however, smoking did not affect free T4 levels or the positivity for TPO-Ab. The rate of smokers in men was significantly higher in patients with subclinical hyperthyroidism (25%) than in those with subclinical hypothyroidism (10%, p&lt;0.05). Furthermore, the results of the longitudinal study revealed a significant decrease in serum TSH levels one year after the start of smoking in men (p&lt;0.05). Since smoking appears to lower serum TSH levels in Japanese euthyroxinemia subjects careful consideration of the smoking status is needed when evaluating subclinical thyroid function.

BIOLOGICAL EFFECTS OF 131I AND 125I ISOTOPES OF IODINE IN THE RAT

1976 ◽  
Vol 71 (1) ◽  
pp. 109-114 ◽  
Author(s):  
I. DONIACH ◽  
D. J. SHALE
Keyword(s):  
Thyroid Function ◽  
Biological Effects ◽  
Female Rats ◽  
Long Term Effects ◽  
Significant Elevation ◽  
Radioiodine Uptake ◽  
Male And Female ◽  
Male And Female Rats ◽  
Serum Tsh

SUMMARY From the differences in radiation profiles between 131I and 125I isotopes of iodine it would be expected that they would show different effects on thyroid function. The differences should lead to lower rates of thyroid gland destruction with 125I and hence less post-irradiation hypothyroidism. This difference in biological effect has been demonstrated in rats by indirect assessment of thyroid function. In this report the long-term effects of a range of similar doses of 131I and 125I were compared, in male and female rats, by direct assessment of thyroid function. Seventeen months after receiving 25 and 125 μCi of 131I, male and female rats showed significant elevation of serum TSH concentration and a reduction in 3 h radioiodine uptake. Rats receiving 1 and 5 μCi of 131I and all doses of 125I showed no significant changes in thyroid function. These findings confirm the previously reported differences in effect between the 131I and 125I isotopes of iodine in the rat.

Iodide Metabolism and Effects

2020 ◽  
pp. 25-33
Keyword(s):  
Thyroid Hormone ◽  
Thyroid Gland ◽  
Thyroid Hormones ◽  
Dietary Supplement ◽  
Thyroid Function ◽  
Thyroid Stimulating Hormone ◽  
Hormone Synthesis ◽  
Serum Tsh ◽  
Tsh Stimulation ◽  
Sensitive Marker

Iodine (I2) is essential in the synthesis of thyroid hormones T4 and T3 and functioning of the thyroid gland. Both T3 and T4 are metabolically active, but T3 is four times more potent than T4. Our body contains 20-30 mg of I2, which is mainly stored in the thyroid gland. Iodine is naturally present in some foods, added to others, and available as a dietary supplement. Serum thyroid stimulating hormone (TSH) level is a sensitive marker of thyroid function. Serum TSH is increased in hypothyroidism as in Hashimoto's thyroiditis. In addition to regulation of thyroid function, TSH promotes thyroid growth. If thyroid hormone synthesis is chronically impaired, TSH stimulation eventually may lead to the development of a goiter. This chapter explores the iodide metabolism and effects of Hashimoto's disease.

Effects of phenylbutazone on thyroid iodine metabolism in vitro

1980 ◽  
Vol 94 (1) ◽  
pp. 64-70 ◽  
Author(s):  
Héctor M. Targovnik ◽  
Bernardo E. Gluzman ◽  
Aldo H. Coleoni ◽  
Hugo Niepomniszcze
Keyword(s):  
Thyroid Function ◽  
Peroxidase Activity ◽  
Thyroid Peroxidase ◽  
Soluble Enzyme ◽  
Iodide Transport ◽  
Significant Difference ◽  
Soluble Peroxidase ◽  
Iodine Metabolism ◽  
Bovine Thyroid

Abstract. Several alterations of thyroid function parameters have been reported in patients treated with phenylbutazone and we have studied the effect of this drug on the intrathyroidal iodine metabolism. An inhibition of the iodide transport expressed in terms of T/M ratios was observed in bovine thyroid slices incubated with high phenylbutazone concentrations. 10−3m produced 72% inhibition whereas lower concentrations showed no significant difference as compared with controls. Iodotyrosine synthesis was affected by 10−4m and 10−5m phenylbutazone. Formation of iodothyronine synthesis was markedly affected between 10−4m and 10−7m phenylbutazone concentrations. Thyroid peroxidase activity was measured by tyrosine-iodinase, triiodide and guaiacol assays. Soluble, pseudosolubilized and crude peroxidase preparations from bovine glands, as well as the soluble enzyme from human thyroids, have shown inhibition of tyrosine-iodinase activity when incubated with phenylbutazone in concentrations ranging from 10−3m to 10−8m, with a Ki of 4 × 10−6m for bovine thyroid peroxidase and of 6 × 10−6m for human soluble peroxidase. Formation of triiodide was affected between 10−3m and 10−8m phenylbutazone concentrations. Guaiacol peroxidation was scarcely affected by the action of the drug. We have concluded that phenylbutazone affects the intrathyroidal iodine metabolism through the inhibition of thyroid peroxidase in concentrations which are usually present in the sera of patients treated with this drug.

scholarly journals Does foetal gender influence maternal thyroid parameters in pregnancy?

2022 ◽  
Vol 11 (1) ◽  
Author(s):  
Georgiana Sitoris ◽  
Flora Veltri ◽  
Pierre Kleynen ◽  
Malika Ichiche ◽  
Serge Rozenberg ◽  
...  
Keyword(s):  
Reference Range ◽  
Thyroid Autoimmunity ◽  
First Trimester ◽  
Thyroid Peroxidase ◽  
Reference Ranges ◽  
Free T4 ◽  
Cross Sectional ◽  
Maternal Thyroid ◽  
Serum Tsh ◽  
Tsh Levels

Objective It is unknown if foetal gender influences maternal thyroid function during pregnancy. We therefore investigated the prevalence of thyroid disorders and determined first-trimester TSH reference ranges according to gender. Methods A cross-sectional study involving 1663 women with an ongoing pregnancy was conducted. Twin and assisted pregnancies and l-thyroxine or antithyroid treatment before pregnancy were exclusion criteria. Serum TSH, free T4 (FT4) and thyroid peroxidase antibodies (TPOAb) were measured at median (interquartile range; IQR) 13 (11–17) weeks of gestation. Subclinical hypothyroidism (SCH) was present when serum TSH levels were >3.74 mIU/L with normal FT4 levels (10.29–18.02 pmol/L), and thyroid autoimmunity (TAI) was present when TPOAb were ≥60 kIU/L. Results Eight hundred and forty-seven women were pregnant with a female foetus (FF) and 816 with a male foetus (MF). In women without TAI and during the gestational age period between 9 and 13 weeks (with presumed high-serum hCG levels), median (IQR range) serum TSH in the FF group was lower than that in the MF group: 1.13 (0.72–1.74) vs 1.24 (0.71–1.98) mIU/L; P = 0.021. First-trimester gender-specific TSH reference range was 0.03–3.53 mIU/L in the FF group and 0.03–3.89 mIU/L in the MF group. The prevalence of SCH and TAI was comparable between the FF and MF group: 4.4% vs 5.4%; P = 0.345 and 4.9% vs 7.5%; P = 0.079, respectively. Conclusions Women pregnant with an MF have slightly but significantly higher TSH levels and a higher upper limit of the first-trimester TSH reference range, compared with pregnancies with a FF. We hypothesise that this difference may be related to higher hCG levels in women pregnant with a FF, although we were unable to measure hCG in this study. Further studies are required to investigate if this difference has any clinical relevance.

scholarly journals SAT-497 Conversion of Hashimoto’s Thyroiditis to Grave’s Disease: A Case Report

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Tayba S Wahedi ◽  
Najah Younes Douba
Keyword(s):  
Thyroid Function ◽  
Hashimoto’S Thyroiditis ◽  
Hashimoto's Thyroiditis ◽  
Thyroid Peroxidase ◽  
Autoimmune Thyroid ◽  
Grave’S Disease ◽  
Thyroid Uptake ◽  
Common Causes ◽  
Grave's Disease ◽  
Tsh Levels

Abstract Introduction: Hashimoto’s thyroiditis and Grave’s disease are common causes for autoimmune thyroid disease. Conversion from Grave’s disease to hypothyroidism have been previously reported in literature. But development of Grave’s disease after a long standing hypothyroidism rarely occurs.Case report: a 22 -year-old Saudi pregnant female patient, was diagnosed with subclinical hypothyroidism with positive anti -thyroid peroxidase antibodies (Anti-TPO) in 2009. She was started on thyroxin and eventually became euthyroid with normal TSH levels till 2016. During subsequent follow-ups, patient was increasingly complaining of palpitations, weight loss and fine tremors. Thyroid function revealed increasingly suppressed TSH levels and over-replacement was suspected. Thyroxin dose was then gradually reduced and finally stopped for few months. Yet her symptoms persisted. Repeated thyroid function showed suppressed TSH level and elevated T4, T3 levels in keeping with overt hyperthyroidism. Thyroid scan further confirmed the diagnosis with diffuse thyroid uptake suggestive of Grave’s disease.Patient was started on medical treatment initially, then successfully treated with radioactive ablation.Conclusion: Although it rarely occurs, possibility of conversion from hypothyroidism to hyperthyroidism should always be kept in mind while treating hypothyroid patients with persistent clinical or biochemical evidence of hyperthyroidism despite dose reduction.References:[1] McLachlan SM. Rapoport B. Thyrotropin-blocking autoantibodies and thyroid-stimulating autoantibodies: Potential mechanisms involved in the pendulum swinging from hypothyroidism to hyperthyroidism or vice versa. Thyroid. 2013;23(1):14-24.[2] Ohye H, Nishihara E, Sasaki I, et al. Four cases of Graves’ disease which developed after painful Hashimoto’s thyroiditis. Intern Med. 2006;45(6):385-9.

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