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Étude critique de la méthode de reddy et de quelques variantes pour le dosage des 17(a),21-dihydroxy-20-cétostéroides urinaires

par Hebbelynck, Marcel
Référence Clinica chimica acta, 5, 6, page (862-878)
Publication Publié, 1960-11

Article révisé par les pairs

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Résumé :

The method of Reddy for the determination of the urinary 17(α),2I-dihydroxy-20-ketosteroids, as well as some modifications of this method, were subjected to a critical experimental examination. After an extensive study of the various steps in the method, the conditions that seemed to offer the greatest advantages were selected and a method of procedure was evolved, which includes the following innovations: (i) the use of a n-butanol for which the Porter-Silber-blank, the sulphuric acidblank and their difference at 406 mμ, in comparison with distilled water, for a thickness of IO mm, do not exceed the respective optical densities of 0.008-0.004 and 0.004 (less if possible). These values are fairly easily attained by purifying the solvent by distillation from 2,4-dinitrophenylhydrazine and sulphuric acid. (2) Saturation of the n-butanol with water and sodium sulphate, prior to the extraction of the urine. The blanks and standards are prepared with the n-butanol thus obtained. (3) Performance of the Porter-Silber reaction at 25°, for 20 h, with 20 N sulphuric acid (exact concentration). (4) Reading of the optical densities at a wavelength of 406 mμ. The modified method was submitted to various tests with regard to the following points: (1) reproducible results. (2) Recovery of free 17(α), 21-dihydroxy-20-ketosteroids from aqueous solutions and after addition to urine. (3) Recovery of sodium tetrahydrocortisoneglucuronide added to urine. (4) Efficiency of the method in detecting variations of concentration in urine (additions to and dilution of urines). Finally the proposed technique was used to determine: (I) The normal values of the urinary excretion of 17(α), 21-dihydroxy-20-ketosteroids in men and women engaged in normal activities. (2) The daily urinary excretion of these steroids in two normal persons followed throughout 15 days of normal active life. (3) The effect of ACTH on the urinary excretion of 17(α), 21-dihydroxy-20-ketosteroids. © 1960.