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| Grozovsky,R.; Morales,M.M.; Carvalho,D.P.. |
| Insulin receptor substrate-1 (IRS-1) is the main intracellular substrate for both insulin and insulin-like growth factor I (IGF-I) receptors and is critical for cell mitogenesis. Thyrotropin is able to induce thyroid cell proliferation through the cyclic AMP intracellular cascade; however, the presence of either insulin or IGF-I is required for the mitogenic effect of thyroid-stimulating hormone (TSH) to occur. The aim of the present study was to determine whether thyroid IRS-1 content is modulated by TSH in vivo. Strikingly, hypothyroid goitrous rats, which have chronically high serum TSH levels (control, C = 2.31 ± 0.28; methimazole (MMI) 21d = 51.02 ± 6.02 ng/mL, N = 12 rats), when treated with 0.03% MMI in drinking water for 21 days, showed... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Thyroid; Goiter; Insulin receptor substrate; Insulin; Thyrotropin. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2007000500011 |
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| Carvalho,D.P.; Ferreira,A.C.F.; Coelho,S.M.; Moraes,J.M.; Camacho,M.A.S.; Rosenthal,D.. |
| Normal in vitro thyroid peroxidase (TPO) iodide oxidation activity was completely inhibited by a hydrolyzed TPO preparation (0.15 mg/ml) or hydrolyzed bovine serum albumin (BSA, 0.2 mg/ml). A pancreatic hydrolysate of casein (trypticase peptone, 0.1 mg/ml) and some amino acids (cysteine, tryptophan and methionine, 50 µM each) also inhibited the TPO iodide oxidation reaction completely, whereas casamino acids (0.1 mg/ml), and tyrosine, phenylalanine and histidine (50 µM each) inhibited the TPO reaction by 54% or less. A pancreatic digest of gelatin (0.1 mg/ml) or any other amino acid (50 µM) tested did not significantly decrease TPO activity. The amino acids that impair iodide oxidation also inhibit the TPO albumin iodination activity. The inhibitory amino... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Thyroid; Thyroperoxidase; Amino acids; Iodide oxidation; Lactoperoxidase. |
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2000000300015 |
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