Data/hora: 11/06/2024 07:14:27

Provedor de dados: | 48
País: | Chile
Título: | Effects of g-hexachlorocyclohexane and L-3,3',5- triiodothyronine on rat liver cytochrome P4502E1- dependent activity and content in relation to microsomal superoxide radical generation
Autores: | FERNÁNDEZ,VIRGINIA; MASSA,LAURA; QUIÑONES,LUIS; SIMON-GIAVAROTTI,KARIN A; GIAVAROTTI,LEANDRO; D'ALMEIDA,VÂNIA; AZZALIS,LIGIA A; JUNQUEIRA,VIRGINIA BC; VIDELA,LUIS A.
Data: | 2003-01-01
Ano: | 2003
Palavras-chave: | G-Hexachlorocyclohexane L-3; 3'; 5-Triiodothyronine Superoxide radical Cytochrome P4502E1 Rat liver.
Resumo: | Liver microsomal cytochrome P4502E1-dependent p-nitrophenol (PNP) hydroxylation and expression of cytochrome P4502E1 were studied in rats subjected to g-hexachlorocyclohexane (HCCH) or L-3,3,,5-triiodothyronine (T3) administration as a possible mechanism contributing to superoxide radical (O2.-) generation. HCCH treatment (a single dose of 40 mg/kg body wt) produced a 43% increase in the content of total cytochrome P450, whereas T3 (daily doses of 0.1 mg/kg body wt for two consecutive days) led to a 37% decrease. NADPH-dependent O2.- generation was elevated by HCCH and T3, expressed as either per mg of protein or per nmol of cytochrome P450, with a 135% enhancement in the O2.- production/superoxide dismutase (SOD) activity ratios being observed in both conditions. This was partly due to depression of SOD activity. Concomitantly, the molecular activity of NADPH-cytochrome p450 reductase was enhanced by 90 and 69% by HCCH and T3, respectively. In these conditions, microsomal PNP hydroxylation showed increases of 58 and 45% in HCCH- and T3-treated rats over control values, respectively, with a parallel 31% (HCCH) and 41% (T3) enhancement in the content of cytochrome P4502E1 assessed by western immunoblotting. We conclude that HCCH and T3 enhance the expression and activity of cytochrome P4502E1 and that of NADPH-cytochrome P450 reductase in rat liver, regardless of the changes in total cytochrome P450 content, representing major contributory mechanisms to microsomal NADPH-dependent O2.- generation
Tipo: | Journal article
Idioma: | Inglês
Identificador: | http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602003000300007
Editor: | Sociedad de Biología de Chile
Formato: | text/html
Fonte: | Biological Research  v.36 n.3-4 2003