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Cassiano NM, Cass QB, Degani ALG, Wainer IW. Determination of the plasma levels of metyrapone and its enantiomeric metyrapol metabolites by direct plasma injection and multidimensional achiral-chiral chromatography. Chirality 2002; 14:731-5. [PMID: 12237834 DOI: 10.1002/chir.10133] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The development and validation of a direct injection high-performance liquid chromatographic (HPLC) method, with column switching, for the determination of metyrapol enantiomers and metyrapone in human plasma is described. The system used in this work was composed of a restricted access media (RAM) bovine serum albumin (BSA) octyl column coupled to an amylose tris(3,5-dimethoxyphenylcarbamate) chiral column. Water was used as eluent for the first 5 min at a flow rate of 1.0 ml/min for the elution of the plasma proteins and then acetonitrile-water (30:70 v/v) for the transfer and analysis of metyrapol enantiomers and metyrapone, which were detected by UV at lambda = 260 nm. The total analysis time was about 32 min. The calibration curves for each enantiomer and for the metyrapone were linear in the ranges 0.075-0.75 microg/ml and 0.150-1.50 microg/ml, respectively. Recoveries, intra- and interday precision and accuracy were determined using three quality controls, one low (0.18 microg/ml), one medium (0.75 microg/ml), and one high (1.35 microg/ml) plasma concentration. Quantitative recoveries and good precision and accuracy were obtained. The limit of quantitation were 0.045 microg/ml for both enantiomers and for the metyrapone.
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Affiliation(s)
- Neila M Cassiano
- Departamento de Química, Universidade Federal de São Carlos, SP, Brazil
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Nnane IP, Tsai MC, Lin G, Damani LA, Mitterhauser M, Zolle I. Pharmacokinetics of 2-methoxyphenylmetyrapone and 2-bromophenylmetyrapone in rats. Eur J Drug Metab Pharmacokinet 1999; 24:23-9. [PMID: 10412888 DOI: 10.1007/bf03190007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The pharmacokinetics of two 2-substituted phenylmetyrapone analogues, 2-methoxyphenylmetyrapone (2-MPMP) and 2-bromophenylmetyrapone (2-BrPMP), developed as potential adrenal imaging agents, were investigated in conscious male rats following an intravenous dose of 25 mg/kg. Arterial blood samples (0.25 ml) were collected at various intervals for up to 7 h after dose and subjected to reversed-phase HPLC analysis. Blood concentrations versus time profile for each compound was determined and the pharmacokinetic parameters calculated using the model-independent approach. Blood concentrations of 2-MPMP declined biexponentially with mean initial (t1/2alpha) and terminal (t1/2beta) half-lives of 3.6 and 23.1 min, respectively. The corresponding area under the curve (AUC(0-infinity)) was 159.3 microg x min/ml, the total blood clearance (CI) was 158.3 ml/min and the volume of distribution (Vd) was 5.2 l. Two metabolites of 2-MPMP, namely 2-hydroxyphenylmetyrapone (2-OHPMP) and 2-methoxyphenylmetyrapone N-oxide (2-MPMP-NO), were detected in the blood and their elimination from blood was almost parallel to that of the parent compound. The maximum blood concentrations (Cmax) of 2-OHPMP and 2-MPMP-NO were approximately 0.9 and 1.7 microg/ml, respectively. Blood concentrations of 2-BrPMP declined monoexponentially with a mean t1/2beta of 12.0 min. The pharmacokinetic parameters for 2-BrPMP were: AUC(0-infinity), 193.7 microg x min/ml; Cl, 131.7 ml/min and Vd, 2.3 l. 2-Bromophenylmetyrapone N-oxide was the only one metabolite detected in the blood, its Cmax and AUC0-infinity were 10.1 microg/ml and 1690.0 microg x min/ml, respectively.
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Affiliation(s)
- I P Nnane
- Department of Pharmacology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories
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Damani LA, Tsai MC, Lin G, Mitterhauser M, Zolle I. Simultaneous analysis of 2-methoxyphenylmetyrapone and its seven potential metabolites by high-performance liquid chromatography. J Chromatogr B Biomed Sci Appl 1997; 704:315-323. [PMID: 9518165 DOI: 10.1016/s0378-4347(97)00491-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
A sensitive and specific high-performance liquid chromatographic (HPLC) assay has been developed for the quantification of 2-methoxyphenylmetyrapone (2-MPMP) and its seven potential metabolites in rat urine and whole blood. 2-MPMP, 2-hydroxyphenylmetyrapone and their N-oxides, together with 2-methoxyphenylmetyrapol, 2-hydroxyphenylmetyrapol and their N-oxides were separated on an Isco Spherisorb ODS-2 reversed-phase column (250 x 4.6 mm, I.D., 5 microm), with an Isco Spherisorb ODS-2 guard cartridge (10 x 4.6 mm I.D.). A gradient elution was employed using solvent system A (acetonitrile-water-triethylamine-acetic acid, 27.3:69.1:0.9:2.7%, v/v) and solvent system B (methanol), the gradient program being as follows: initial 0-4 min A:B=74:26; 4-10 min linear change to A:B=50:50; 10-16 min maintain A:B=50:50; 16 min return to initial conditions (A:B=74:26). Flow-rate was maintained at 1.25 ml/min, and the eluent monitored using a diode array multiple wavelength UV detector set at 260 nm. Most of the analytes were baseline resolved, and analysis of samples recovered from blood or urine (pH 12, 3 x 5 ml of dichloromethane, recovery approximately 20-95%) revealed no interference from any co-extracted endogenous compounds in the biological matrices, except for 2-hydroxyphenylmetyrapol N-oxide (2-OHPMPOL-NO) at low concentrations. The calibrations (n=6) were linear (r > or = 0.996) for all analytes (approximately 0.5-100 microg/ml), with acceptable inter- and intra-day variability. Subsequent validation of the assay revealed acceptable precision, as measured by coefficient of variation (C.V.) at the low (0.5 mg/ml), medium (50 microg/ml) and high (100 microg/ml) concentrations. The limits of detection for 2-MPMP and their available potential metabolites, except 2-OHPMPOL-NO, in rat urine and blood were both 0.5 microg/ml, respectively.
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Affiliation(s)
- L A Damani
- Department of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories
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Chiarotto JA, Wainer IW. Determination of metyrapone and the enantiomers of its chiral metabolite metyrapol in human plasma and urine using coupled achiral-chiral liquid chromatography. J Chromatogr B Biomed Appl 1995; 665:147-54. [PMID: 7795785 DOI: 10.1016/0378-4347(94)00500-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A coupled achiral-chiral liquid chromatographic assay has been developed to determine the concentrations of metyrapone and the enantiomers of its chiral metabolite metyrapol in plasma and urine. The chromatographic system consisted of a silica precolumn (75 x 4.6 mm I.D.) coupled in-line to a 250 x 4.6 mm I.D. column containing cellulose tris(4-methylbenzoate) coated on silica gel (Chiralcel OJ-CSP). When plasma samples were analyzed, the mobile phase was hexane-ethanol (92:8, v/v) modified with 0.1% diethylamine and when urine samples were analyzed the mobile phase was hexane-ethanol (94:6, v/v) modified with 0.2% diethylamine. Under these chromatographic conditions the chromatographic retentions [expressed as capacity factors (k')] for metyrapone were k' = 2.35 (plasma) and 2.52 (urine); for (-)-metyrapol k' = 4.22 (plasma) and 4.62 (urine); for (+)-metyrapone k' = 5.16 (plasma) and 5.86 (urine); enantioselectivities (alpha) were 1.09 (plasma) and 1.13 (urine). The assay has been validated for use in metabolic studies. The analyses of plasma and urine samples from one subject following oral administration of 750 mg of metyrapone indicated that the enzymatic reduction of myterapone by aldo-keto reductase was enantiospecific.
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Affiliation(s)
- J A Chiarotto
- Department of Oncology, McGill University, Montreal, Que, Canada
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Yu J, Zolle I, Mertens J, Rakias F. Synthesis of 2-[131I]iodophenyl-metyrapone using Cu(I)-assisted nucleophilic exchange labelling: study of the reaction conditions. Nucl Med Biol 1995; 22:257-62. [PMID: 7767321 DOI: 10.1016/0969-8051(94)00090-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
2-Bromophenyl-metyrapone has been synthesized as a precursor for Cu(I)-assisted labelling with radioiodine. A labelling yield of > 95% was obtained and the specific activity of the purified product was 120 GBq/mumol. The iodo for bromo exchange requires an excess of reducing agents to maintain the Cu(I) redox potential. The effects of the amount of reactants, temperature and time were studied. The labelling yield showed a direct dependence on the amount of precursor and Cu(+)-catalyst used for the reaction, and an increase with reaction time (optimal at 60 min) and temperature (optimal at 100 degrees C). Studies of the stability, lipophilicity and binding of 2-[131I]iodophenyl-metyrapone to serum protein indicated high in vitro stability, high lipophilicity (log P = 2.19) and a loose association with serum proteins.
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Affiliation(s)
- J Yu
- Univ. Klinik f. Nuclearmedizin, Allgemeines Krankenhaus, Vienna, Austria
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Usansky JI, Damani LA. Assay of metyrapone, metyrapol and the isomeric mono-N-oxides of metyrapone in biological fluids by high-performance liquid chromatography. J Chromatogr 1991; 563:283-98. [PMID: 2055992 DOI: 10.1016/0378-4347(91)80035-b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A sensitive high-performance liquid chromatographic (HPLC) method for the analysis of metyrapone [2-methyl-1,2-di-(3-pyridyl)-1-propanone], its reduced metabolite metyrapol and metyrapone mono-N-oxide metabolites in biological fluids is reported. These components were extracted into dichloromethane (2 x 5 ml) from alkalinised microsomal incubates, urine and blood (final pH about 12.5), or from cytosolic incubates at pH 7.4 (final aqueous volume 2-4 ml). Recoveries were in the range 70-100% under these conditions. The intact drug and metabolites were separated by reversed-phase HPLC with ultraviolet detection at 261 nm. All calibration curves were linear (correlation coefficient greater than 0.997). For the analysis of hepatic microsomal or cytosolic incubates, the coefficient of variation was less than 10% for samples over the range 2.5-250 nmol/ml N-oxides and 10-250 nmol/ml metyrapol. Measurement of metyrapone and metyrapol in rat blood (0.25-ml sample volume) was linear in the ranges 4.4-265 and 26-263 nmol/ml, respectively, the lower concentration being the limit of detection. The coefficient of variation was less than 20% for samples over the ranges tested for both these compounds. The N-oxide metabolites were not detectable in blood using this assay, their concentrations being below the limit of detection.
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Affiliation(s)
- J I Usansky
- Department of Pharmacy, University of Manchester, U.K
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Ichimura K. [Studies on the hypothalamo-pituitary adrenal axis in children by using 11-beta-hydroxylase inhibitors. I. A gas chromatograph-mass spectrometric method for the determination of serum metyrapone and reduced metyrapone; a pharmacokinetic and biological study of metyrapone in children]. Nihon Naibunpi Gakkai Zasshi 1983; 59:715-737. [PMID: 6604667 DOI: 10.1507/endocrine1927.59.5_715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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Ichimura K. [Studies on the hypothalamo-pituitary-adrenocortical axis in children using 11-beta-hydroxylase inhibitors. II. Studies of the age-differences of the development of the hypothalamo-pituitary-adrenocortical axis--a comparison of the glucocorticoid pathway to the mineralcorticoid pathway]. Nihon Naibunpi Gakkai Zasshi 1983; 59:738-55. [PMID: 6604668 DOI: 10.1507/endocrine1927.59.5_738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Dammacco F, Rigillo N, Pentasuglia N, Zimbalatti F. [Plasma concentrations of metopirone after oral administration in the child]. Minerva Pediatr 1976; 28:1334-6. [PMID: 948331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Lundberg PO, Wide L. [Results of some neuroendocrinological studies in patients with anatomically verified hypothalamic disorders]. Ginekol Pol 1974; 45:953-9. [PMID: 4212801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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Dammacco F, Rigillo N, Pentasuglia N, Zimbalatti F. [Behavior of plasma levels of metopirone after oral administration in children]. Boll Soc Ital Biol Sper 1974; 50:310-4. [PMID: 4447740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Dammacco F, Rigillo N, Pentasuglia N, Zimbalatti F. [Effect of oral administration of metopirone on somatotropic hormone and on carbohydrate metabolism in children]. Boll Soc Ital Biol Sper 1974; 50:315-20. [PMID: 4447741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Hollands TR, Johnson WJ. A gas chromatographic method for the determination of metyrapone and its reduced derivative in plasma. Biochem Med 1973; 7:288-91. [PMID: 4704464 DOI: 10.1016/0006-2944(73)90085-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Jubiz W, Matsukura S, Meikle AW, Harada G, West CD, Tyler FH. Plasma metyrapone, adrenocorticotropic hormone, cortisol, and deoxycortisol levels. Sequential changes during oral and intravenous metyrapone administration. Arch Intern Med 1970; 125:468-71. [PMID: 4313727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Jubiz W, Levinson RA, Meikle AW, West CD, Tyler FH. Absorption and conjugation of metyrapone during diphenylhydantoin therapy: mechanism of the abnormal response to oral metyrapone. Endocrinology 1970; 86:328-31. [PMID: 4311903 DOI: 10.1210/endo-86-2-328] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Meikle AW, Jubiz W, Matsukura S, West CD, Tyler FH. Effect of diphenylhydantoin on the metabolism of metyrapone and release of ACTH in man. J Clin Endocrinol Metab 1969; 29:1553-8. [PMID: 4310497 DOI: 10.1210/jcem-29-12-1553] [Citation(s) in RCA: 44] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Meikle AW, Jubiz W, West CD, Tyler FH. A simple fluorometric method for assay of plasma metyrapone. J Lab Clin Med 1969; 74:515-20. [PMID: 5806980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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Abstract
ABSTRACT
The impaired response to metyrapone during ethinyloestradiol administration has been studied in a further seven patients. A two day metyrapone test was done in the control period and then when the patient was receiving ethinyloestradiol 0.1 mg daily. In four of the patients the metyrapone tests were repeated in the control and oestrogen periods, but with the addition of an 8-hour infusion of ACTH on each of the metyrapone days. The 17-hydroxycorticosteroids excreted in the urine were converted to 17-oxosteroids using Few's method, chromatographed, and the 11β-hydroxyaetiocholanolone and aetiocholanolone fractions eluted and measured. Any change in the degree of 11β-hydroxylase inhibition by metyrapone should be reflected in a change in the ratio of 11β-hydroxyaetiocholanolone to aetiocholanolone, as these are derived from the metabolites of cortisol and 11-deoxycortisol respectively. It was found that this ratio was higher when metyrapone was administered during the oestrogen period than when it was administered during the control period. The effect was still seen when the adrenal cortex was maximally stimulated with ACTH during the periods of metyrapone administration.
It is concluded that oestrogen administration impairs 11β-hydroxylase inhibition by metyrapone, possibly as a result of increased 11β-hydroxylase activity in the adrenal cortex.
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