%0 Journal Article %T Actividad del citocromo P450 y su alteraci¨®n en diversas patolog¨ªas Cytochrome P450 activity and its alteration in different diseases %A Myriam Orellana B %A Viviana Guajardo T %J Revista m¨¦dica de Chile %D 2004 %I Sociedad M¨¦dica de Santiago %X Cytochrome P450 (CYP) enzymes participate in the metabolism of a variety of naturally occurring and foreign compounds by reactions requiring NADPH and O2. The diversity of reactions catalyzed and its extensive substrate specificity render CYP enzymes as one of the most versatile known catalysts. Individual members of the CYP superfamily are expressed in almost every cell type in the body. As compared to hepatic enzymes, the regulation of human extrahepatic CYPs has not been so well studied. In general, the levels of some hepatic CYP enzymes are depressed by diseases, causing potential and documented impairment of drug clearence and clinical drug toxicity. However, modulation of CYPs is enzyme selective and this selectivity differs in different diseases. This article reviews some basic concepts about CYP and its regulation in some disease states such as hypertension, diabetes, obesity and hepatic, infectious and inflammatory diseases (Rev M¨¦d Chile 2004; 132: 85-94). %K Cytochrome P450 %K Enzyme induction %K Xenobiotics %U http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872004000100014