Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P20020 (adenosine triphosphatase)
 3,299 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The authors have examined the enzyme histochemical staining of surgically removed human thyroid tissue in an attempt to identify markers that might be useful in the histopathologic diagnosis of thyroid neoplasms. Fresh thyroid glands and other tissues were fixed in cold (4 degrees C) 4% paraformaldehyde and embedded in glycol methacrylate. Forty-two specimens were studied in thin sections, which gave excellent histologic detail and enzyme preservation. Cytologic detail was similar to that in Papanicolaou-stained smears, with good definition of nuclear inclusions and grooves, particularly in cases of papillary carcinoma. The enzyme histochemical reactions studied were as follows: adenosine triphosphatase, alkaline and acid phosphatases, alpha-naphthyl acetate esterase, and 5'-nucleotidase. Thyroid epithelial cells and the benign neoplasms derived from them were typically positive for 5'-nucleotidase, alpha-naphthyl acetate esterase, and acid phosphatase, and negative for adenosine triphosphatase and alkaline phosphatase. Staining for adenosine triphosphatase was present in papillary and follicular carcinomas and was seen in benign glands only under certain circumstances such as Graves' disease. The adenosine triphosphatase reaction therefore appears to be helpful in distinguishing between benign and malignant neoplasms derived from thyroid epithelium in humans and may be a useful adjunct to routine morphology.
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PMID:Enzyme histochemistry and thyroid neoplasia. 301 Jun 99

The transport of iodide into the thyroid, catalyzed by the Na+/I- symporter (NIS), is the initial and rate-limiting step in the formation of thyroid hormones. To study the basic characteristics of the human (h) NIS, we have established a Chinese hamster ovary cell line stably expressing the hNIS (CHO-NIS9). In agreement with previous work on the rat NIS, iodide uptake in these cells was initiated within 2 min of the addition of 131I, reaching a plateau after 30 min. Both perchlorate and thiocyanate inhibited iodide uptake in a dose-dependent manner, with inhibition evident at concentrations of 0.01 and 0.1 micromol/L, respectively, and reaching complete inhibition at 20 micromol/L and 500 micromol/L, respectively. Ouabain, which blocks the activity of the Na+/K+ adenosine triphosphatase, also inhibited iodide uptake in a dose-dependent manner, starting at concentrations of 100 micromol/L and reaching maximum inhibition at 1600 micromol/L, indicating that iodide uptake in these cells is sodium dependent. CHO-NIS9 cells were further used to study 88 sera from patients with Graves' disease, for iodide uptake inhibitory activity, which were compared with sera from 31 controls. Significant iodide uptake inhibition was taken as any inhibition in excess of the mean + 3 SD of the results with the control sera. On this basis, 27 (30.7%) of the Graves' sera, but none of the controls, inhibited iodide uptake in CHO-NIS9. IgGs from these patients also inhibited iodide uptake, indicating that this inhibitory activity was antibody mediated. In summary, we have established a CHO cell line stably expressing the hNIS and shown that antibodies in GD sera can inhibit iodide uptake in these cells. This further emphasizes the role of NIS as a novel autoantigen in thyroid immunity.
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PMID:The modulation of the human sodium iodide symporter activity by Graves' disease sera. 954 44