|
|
|
|
|
| Nascimento-Saba,C.C.A.; Brito,A.C.; Pereira,M.J.S.; Carvalho,J.J.; Rosenthal,D.. |
| Previous studies have shown that in vitro thyroid peroxidase (TPO) iodide oxidation activity is decreased and thyroid T4-5'-deiodinase activity is increased 15 days after induction of experimental diabetes mellitus (DM). In the present study we used thyroid histoautoradiography, an indirect assay of in vivo TPO activity, to determine the possible parallelism between the in vitro and in vivo changes induced by experimental DM. DM was induced in male Wistar rats (about 250 g body weight) by a single ip streptozotocin injection (45 mg/kg), while control (C) animals received a single injection of the vehicle. Seven and 30 days after diabetes induction, each diabetic and control animal was given ip a tracer dose of 125I (2 µCi), 2.5 h before thyroid excision.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Thyroid; Diabetes mellitus; Autohistoradiography; Rat. |
| Ano: 1998 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1998000200013 |
| |
|
|
| 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 |
| |
|
|
|
