RESUMEN
Adrenocortical carcinoma (ACC) is a rare malignancy with an incompletely understood pathogenesis and a poor prognosis. The adrenalytic activity of mitotane has made it the most important single drug in the treatment of ACC. Unfortunately, the exact mechanism of mitotane action is still unknown. It is believed that mitotane belongs to the class of drugs that require metabolic transformation by cytochrome P450 for therapeutic action; therefore determination of plasma levels of not only mitotane but also its metabolites would help in carrying out the treatment. The objective of this work was to develop and validate an SPE-HPLC method for simultaneous determination of mitotane and its metabolites in different biological fluids. The sample preparation consisted of a solid-phase extraction on a Discovery DSC(18) cartridge, while analysis of extracts was performed on a Symmetry C(18) column. The usefulness of the proposed method was confirmed by analysis of plasma, red cell and urine samples from patient chronically treated with 1.5 g of mitotane. The patient involved in this study had a high plasma concentration of mitotane and none of the investigated metabolites were found. In order to investigate whether the polymorphism of CYP2C9 and CYP2C19 enzymes could be related to the metabolism of mitotane, RT-PCR analysis was performed.
Asunto(s)
Antineoplásicos Hormonales/sangre , Antineoplásicos Hormonales/orina , Cromatografía Líquida de Alta Presión/métodos , Mitotano/sangre , Mitotano/orina , Extracción en Fase Sólida/métodos , Administración Oral , Neoplasias de la Corteza Suprarrenal/sangre , Neoplasias de la Corteza Suprarrenal/tratamiento farmacológico , Neoplasias de la Corteza Suprarrenal/genética , Neoplasias de la Corteza Suprarrenal/orina , Carcinoma Corticosuprarrenal/sangre , Carcinoma Corticosuprarrenal/tratamiento farmacológico , Carcinoma Corticosuprarrenal/genética , Carcinoma Corticosuprarrenal/orina , Hidrocarburo de Aril Hidroxilasas/genética , Citocromo P-450 CYP2C19 , Citocromo P-450 CYP2C9 , Estabilidad de Medicamentos , Femenino , Humanos , Modelos Lineales , Persona de Mediana Edad , Reacción en Cadena en Tiempo Real de la Polimerasa , Reproducibilidad de los ResultadosRESUMEN
Urine samples were obtained from four patients with Cushing's syndrome who had been treated with o,p'-DDD[2,2-(2-chlorophenyl,4'-chlorophenyl)1,1-dichloroethane]. Methylthio-containing (MC) metabolites and other metabolites of o,p'-DDD were detected in the urine samples by gas chromatographic mass spectrometry. These MC metabolites showed smaller peaks in the gas chromatogram than other peaks derived from other metabolites of o,p'-DDD. Although the biological significance of the pathway forming these MC metabolites is not known at present, the mechanism of the metabolic pathway was discussed.
Asunto(s)
Síndrome de Cushing/orina , Mitotano/orina , Femenino , Cromatografía de Gases y Espectrometría de Masas , Humanos , Inactivación Metabólica , Masculino , MetilaciónRESUMEN
The metabolism of 14C-labeled 1-(p-chlorophenyl)-2,2-dichloroethane (o,p'-DDD) in rats was investigated. Metabolites were identified in feces and urine extracts by thin-layter chromatography (TLC), gas-liquid chromatography, and mass spectropmetry. Extracts of acidic metabolites were methylated with diazomethane for identification. Metabolites were quantitated by TLC and liquid scintillation counting. After a 100-mg oral dose to each of three rats, an average of 7.1% of the radioactivity was excreted in the urine and 87.8% in the feces within 8 days. The urine was found to contain o,p'-dichlorodiphenylacetic acid (o,p'-DDA) as well as 4-hydroxy-, 3-hydroxy-, and 3,4-dihydroxy-substituted o,p'-DDA. The serine and glycine conjugates of o,p'-DDA were also identified. In addition to the above metabolites the feces contained o,p'-DDD. 1-(o-chlorophenyl)-1-(P-chlorophenyl)-2-chloroethylene, and the aspartic acid conjugate of o,p'-DDA. The presence of aromatic mono- and dihydroxylated o,p'-DDD was also detected in feces.