Peroxidase activity and thyroglobulin iodination activity of thyroid peroxidase in non-functioning thyroid tumours

1988 ◽  
Vol 118 (1) ◽  
pp. 147-153 ◽  
Author(s):  
Hirokatsu Yoshimura ◽  
Kunihiko Ito ◽  
Osamu Tarutani ◽  
Toichiro Hosoya
Keyword(s):  
Peroxidase Activity ◽  
Thyroid Tissue ◽  
Assay Method ◽  
Considerable Proportion ◽  
Thyroid Peroxidase ◽  
Oxidation Activity ◽  
Rapid Assay ◽  
Iodide Transport ◽  
Iodide Oxidation ◽  
Transport Defect

Abstract. Both lesion (L) and adjacent normal (N) thyroid tissue from 48 patients with non-functioning adenomas and adenomatous goitres were assayed for peroxidase activity by the 'mini' assay method employing guaiacol or iodide as the second substrate. A considerable proportion of thyroids (46% of adenomas and 22% of adenomatous goitres) demonstrated no iodide oxidation activity in L although they had guaiacol oxidation activity, and these were grouped as subgroups A. The rest of these non-functioning tumours, termed subgroups B, had both guaiacol and iodide oxidation activity which was higher (3.0–4.6 times in guaiacol assay and 7.3–14.1 times in iodide assay) in L than in N. These data indicate that the non-functioning in subgroups A may be due to a lack of iodide oxidation activity and that some other defects such as an iodide transport defect may be involved in subgroups B. Furthermore, a precise and rapid assay method for thyroglobulin iodination activity of thyroid peroxidase was developed, with modifications of previous methods. On the basis of this method, we found that there is a good correlation (r = 0.94) between iodide oxidation assay and thyroglobulin iodination assay, leading to the conclusion that thyroglobulin iodination assay can be replaced by iodide oxidation assay.

scholarly journals A rapid assay of human thyroid peroxidase activity

2020 ◽  
Vol 62 ◽  
pp. 104662 ◽  
Author(s):  
Hongyan Dong ◽  
Marlena Godlewska ◽  
Michael G. Wade
Keyword(s):  
Peroxidase Activity ◽  
Human Thyroid ◽  
Thyroid Peroxidase ◽  
Rapid Assay ◽  
Human Thyroid Peroxidase

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.

Inhibition by immunoglobulin G of synthesis of thyroid hormone in thyroid cultures from hypothyroid patients with goitrous Hashimoto's thyroiditis

1990 ◽  
Vol 123 (5) ◽  
pp. 511-518 ◽  
Author(s):  
Jaeduk Noh ◽  
Noboru Hamada ◽  
Hifumi Saito ◽  
Midori Yoshimoto ◽  
Hiroyuki Iwasaki ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Peroxidase Activity ◽  
Immunoglobulin G ◽  
Hashimoto’S Thyroiditis ◽  
Thyroid Tissue ◽  
Hashimoto's Thyroiditis ◽  
Thyroid Peroxidase ◽  
Hormone Synthesis ◽  
Microsomal Antibody ◽  
Hypothyroid Patients

Abstract. Recently, thyroid microsomal antigen was identified as thyroid peroxidase, and thyroid microsomal antibody was found to inhibit thyroid peroxidase activity in vitro. We investigated the possibility that anti-microsomal antibody inhibits the iodination of tyrosine, in vivo. Immunoglobulin G with or without anti-microsomal antibody from hypothyroid patients with goitrous Hashimoto's thyroiditis inhibited thyroid hormone synthesis in cultured slices of normal human thyroid tissue. IgGs with anti-microsomal antibody inhibited 125I thyroidal uptake and thyroid hormone synthesis stimulated by TSH more than normal IgG did. However, the same results were obtained with IgGs without anti-microsomal antibody. This effect did not involve anti-microsomal antibody, anti-thyroglobulin antibody, TSH-binding inhibitor immunoglobulin, thyroid stimulation-blocking immunoglobulin, or the cAMP level of the thyroid tissue. The ratio of organic I to inorganic I with stimulation by TSH in slices incubated with IgG from hypothyroid patients with goitrous Hashimoto's thyroiditis or normal IgG was not significantly different, but was significantly higher in slices incubated with methylmercaptoimidazole. Therefore, IgG from hypothyroid patients with goitrous Hashimoto's thyroiditis mainly suppressed 125I thyroidal uptake, rather than inhibiting thyroid peroxidase activity. In addition, this IgG was present in the serum of 11 of the 12 hypothyroid patients with Hashimoto's thyroiditis studied. This IgG may be involved in the mechanism that causes hypothyroidism in some patients with goitrous Hashimoto's disease.

scholarly journals Improved assay method for activity of thyroid peroxidase-catalysed coupling of iodotyrosine residues of thyroglobulin utilizing h.p.l.c. for analysis of iodothyronines

1989 ◽  
Vol 262 (1) ◽  
pp. 209-214 ◽  
Author(s):  
T Ohmori ◽  
O Tarutani ◽  
T Hosoya
Keyword(s):  
Ethyl Acetate ◽  
Peroxidase Activity ◽  
Sodium Cholate ◽  
Human Thyroid ◽  
Assay Method ◽  
Thyroid Peroxidase ◽  
Graves Disease ◽  
Thyroid Glands ◽  
Hydrolysis Of

The coupling of iodotyrosine residues of thyroglobulin (Tg) catalysed by thyroid peroxidase (TPO) has scarcely been studied with respect to the TPO of abnormal human thyroid glands. The present paper proposes a rapid and convenient assay method applicable for determining the coupling activity of a sample of less than 500 mg from each patient's thyroid. The main characteristics of the method are as follows: (i) mitochondrial/microsomal fractions of thyroid glands were treated with sodium cholate plus trypsin, and the supernatants obtained by ultracentrifugation were directly used for the assay of coupling and peroxidase activity of TPO; (ii) the formation of iodotyrosine residues catalysed by TPO was performed by using chemically iodinated Graves'-disease Tg containing 41 iodine atoms per molecule and with a high iodotyrosine and a low iodothyronine content; (iii) newly synthesized iodothyronine residues (thyroxine, 3,5,3′-tri-iodothyronine, and 3,3′,5′-tri-iodothyronine) were analysed by h.p.l.c. after hydrolysis of Tg with proteinases and extraction of iodothyronines with ethyl acetate.

A study of thyroglobulin and peroxidase activity in the thyroid tissue of patients with non-endemic non-toxic nodular goitre

1991 ◽  
Vol 80 (4) ◽  
pp. 301-307 ◽  
Author(s):  
T. Mories ◽  
J. M. Miralles ◽  
A. Reglero ◽  
S. Felipe ◽  
J. J. Corrales ◽  
...  
Keyword(s):  
Peroxidase Activity ◽  
Thyroid Tissue ◽  
Enzymic Activity ◽  
Thyroid Peroxidase ◽  
Carbohydrate Composition ◽  
Nodular Goitre ◽  
Hormone Synthesis ◽  
Control Subjects ◽  
The Mean ◽  
Second Peak

1. A study was made of the activity of the enzyme thyroid peroxidase and of the concentration, carbohydrate composition and the degree of iodination of thyroglobulin in the thyroid glands of 60 patients with non-endemic non-toxic goitre in the nodular phase and in those of 25 control subjects. 2. Thyroid peroxidase activity was determined by the guaiacol assay and was significantly higher in patients with non-endemic non-toxic goitre than in control subjects (3.60 ± 2.51 and 2.07 ± 1.08 μmol of guaiacol oxidized min−1 g−1 of tissue, respectively; ranges 0.16–10.57 and 0.52–4.85 μmol of guaiacol oxidized min−1 g−1 of tissue, respectively; P <0.05). 3. Thyroglobulin was purified by precipitation with ammonium sulphate and Sephadex G-200 gel filtration. Two protein peaks were obtained which were identified as thyroglobulin and measured by radioimmunoassay. The concentration of thyroglobulin in the first peak was 98.94 (SD 84.87, range 0.60–455.54) mg/g of tissue for the patients with non-endemic, non-toxic goitre and 51.41 (SD 28.34, range 14.99–106.39) mg/g of tissue for the control subjects (P <0.01). The second peak showed 1.26 (SD 1.27, range 0.09–6.50) mg of thyroglobulin/mg of tissue for the group with non-endemic non-toxic goitre and 0.51 (SD 0.25, range 0.15–0.98 mg of thyroglobulin/mg of tissue) for the control subjects (P <0.01). 4. The carbohydrate composition of thyroglobulin was determined by acid hydrolysis and colorimetry, evaluating the levels of hexoses, hexosamines and sialic acid. The degree of glycosylation was significantly higher in thyroglobulin from patients with non-endemic non-toxic goitre (mean 16.46%, SD 5.68%, range 8.33–37.3% for the first peak, and mean 16.11%, SD 4.85%, range 5.30–33.10% for the second peak) than that from control subjects (mean 9.62%, SD 1.23%, range 7.56–12.02% for the first peak, and mean 8.68%, SD 0.99%, range 7.24–11.09% for the second peak). The values for each of the carbohydrates were significantly higher in the thyroglobulin from patients with non-endemic non-toxic goitre than in the control subjects, and there was also a positive correlation between them, except for the hexoses and hexosamines in the second peak of the thyroglobulin from the control subjects. 5. The thyroglobulin of the group with non-endemic non-toxic goitre was significantly less iodinated (mean 0.055%, SD 0.038%, range 0.021–0.161% in the first peak, and mean 0.30%, SD 0.22%, range 0.10–0.93% in the second peak) than that of the control subjects (mean 0.32%, SD 0.16%, range 0.07–0.64% in the first peak, and mean 0.77%, SD 0.17%, range 0.37–1.27% in the second peak). 6. A significant negative correlation was observed between the degree of thyroglobulin iodination and thyroid peroxidase activity in control subjects; however, this was not found in patients with non-endemic non-toxic goitre. The mean level of peroxidase activity in the latter group was 26.71% above what would be expected for the mean degree of thyroglobulin iodination found, indicating that other additional factors may govern the increase in enzymic activity. 7. Such findings point to the existence of an alteration in thyroglobulin that may decrease the efficiency of the protein for normal hormone synthesis, and this may be one of the reasons for the development and/or maintenance of non-endemic non-toxic goitre.

Identification of Classifiers for Increase or Decrease of Thyroid Peroxidase Activity in the FTC-238/hTPO Recombinant Cell Line

2011 ◽  
Vol 45 (18) ◽  
pp. 7906-7914 ◽  
Author(s):  
Mee Song ◽  
Youn-Jung Kim ◽  
Mi-Kyung Song ◽  
Han-Seam Choi ◽  
Yong-Keun Park ◽  
...  
Keyword(s):  
Cell Line ◽  
Peroxidase Activity ◽  
Thyroid Peroxidase ◽  
Recombinant Cell Line ◽  
Recombinant Cell

scholarly journals Thyroid Gene Mutations in Pregnant and Breastfeeding Women Diagnosed With Transient Congenital Hypothyroidism: Implications for the Offspring’s Health

2021 ◽  
Vol 12 ◽  
Author(s):  
Maria C. Opazo ◽  
Juan Carlos Rivera ◽  
Pablo A. Gonzalez ◽  
Susan M. Bueno ◽  
Alexis M. Kalergis ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Thyroid Hormones ◽  
Congenital Hypothyroidism ◽  
Gene Mutations ◽  
Genetic Variations ◽  
Hormone Deficiency ◽  
Iodide Transport ◽  
Transport Defect ◽  
Pregnancy And Lactation ◽  
Transient Congenital Hypothyroidism

Fetus and infants require appropriate thyroid hormone levels and iodine during pregnancy and lactation. Nature endorses the mother to supply thyroid hormones to the fetus and iodine to the lactating infant. Genetic variations on thyroid proteins that cause dyshormonogenic congenital hypothyroidism could in pregnant and breastfeeding women impair the delivery of thyroid hormones and iodine to the offspring. The review discusses maternal genetic variations in thyroid proteins that, in the context of pregnancy and/or breastfeeding, could trigger thyroid hormone deficiency or iodide transport defect that will affect the proper development of the offspring.

scholarly journals Subcellular structure of bovine thyroid gland. The localization of the peroxidase activity in bovine thyroid

1978 ◽  
Vol 174 (3) ◽  
pp. 939-949 ◽  
Author(s):  
M J S De Wolf ◽  
A R Lagrou ◽  
H J J Hilderson
Keyword(s):  
Peroxidase Activity ◽  
Buoyant Density ◽  
Thyroid Tissue ◽  
Guaiacol Peroxidase ◽  
Subcellular Structure ◽  
The Third ◽  
Bovine Thyroid ◽  
Two Peaks ◽  
Second Peak ◽  
Membranous Material

1. After differential pelleting of bovine thyroid tissue the highest relative specific activities for plasma membrane markers are found in the L fraction whereas those for peroxidase activities (p-phenylenediamine, guaiacol and 3,3′-diaminobenizidine tetrachloride peroxidases) are found in the M fraction. 2. When M + L fractions were subjected to buoyant-density equilibration in a HS zonal rotor all peroxidases show different profiles. The guaiacol peroxidase activity always follows the distribution of glucose 6-phosphatase. 3. When a Sb fraction is subjected to Sepharose 2B chromatography three major peaks are obtained. The first, eluted at the void volume, consists of membranous material and contains most of the guaiacol peroxidase activity. Most of the protein (probably thyroglobulin) is eluted with the second peak. Solubilized enzymes are recovered in the third peak. 4. p-Phenylenediamine peroxidase activity penetrates into the gel on polyacrylamidegel electrophoresis, whereas guaiacol peroxidase activity remains at the sample zone. 5. DEAE-Sephadex A-50 chromatography resolves the peroxidase activities into two peaks, displaying different relative amounts of the different enzymic activities in each peak. 6. The peroxidase activities may be due to the presence of different proteins. A localization of guaiacol peroxidase in rough-endoplasmic-reticulum membranes (or in membranes related to them) seems very likely.

Resolution of hyperthyroidism and thyroid antibodies following struma ovarii resection: an uncommon entity

2021 ◽  
Vol 14 (4) ◽  
pp. e240924
Author(s):  
Preethi Padmanaban ◽  
Eric Nylen ◽  
Kenneth Burman ◽  
Sabyasachi Sen
Keyword(s):  
Ovarian Cyst ◽  
Thyroid Tissue ◽  
Lower Abdominal Pain ◽  
Ovarian Tumour ◽  
Thyroid Stimulating Hormone ◽  
Thyroid Peroxidase ◽  
Surgical Removal ◽  
Thyroid Function Tests ◽  
Struma Ovarii ◽  
Free T4

We report a case of 34-year-old clinically asymptomatic woman who had been followed for 6 years for hyperthyroidism with thyroid stimulating hormone <0.006 uIU/mL, free T4 1.98 ng/mL, free T3 5.3 pg/mL, elevated thyroid stimulating immunoglobulin 1.70 IU/L, thyroid peroxidase antibody 38 IU/mL and thyroglobulin antibody 9.3 IU/mL. Radioiodine thyroid scan showed minimal uptake in both thyroid lobes (24-hour uptake was 0.3%). She subsequently underwent evaluation for lower abdominal pain and menstrual irregularities, which revealed a large left ovarian cyst measuring 15.9 cm × 10.8 cm × 13.2 cm and right-sided ovarian cyst measuring 2.7 cm × 3.3 cm × 3.5 cm. Laparoscopic bilateral ovarian cystectomy was performed and the final pathology revealed struma ovarii of the left ovarian cyst with the entire ovarian tumour made up of benign thyroid tissue. Thyroid function tests performed 3 months after surgical removal of struma ovarii showed euthyroidism. We present a rare case with detailed laboratory and immunological data before and after ovarian extirpation with resolution of hyperthyroidism associated with functional struma ovarii.

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