A Critical Appraisal of a Method of Estimating Urinary 17-Oxosteroids and Total 17-Oxogenic Steroids

Endocrine effects of high-dose ketoconazole therapy in advanced prostatic cancer

“…Transcortin was measured by radial immunodiffusion (Van Baelen & De Moor 1974) and 5ct-dihydrotestosterone-binding capacity of sex hormone binding globulin (SHBG) by ammonium sulphate precipitation (Heyns & De Moor 1971). 17-hydroxysteroids and 17-ketosteroids in 24 h urine collections were measured by the methods of Metcalf (1963) and Gray et al (1969), respectively. ACTH was assayed by radioimmunoassay using the kit provided by CIS (Gif-Sur-Yvette, France), DHEA sul¬ phate by the radioimmunoassay kit of Cambridge Medi¬ cal Diagnostic (Billerica, USA).…”

Anti-arthritic propionic acid derivatives and 17-oxosteroid measurements—a direct interference

“…Also, the abnormality disappeared within 2 d of stopping the drug, and was suspected to be due to the parent drug, although the possibility of interference from its metabolites could not be excluded. This was confirmed by in vitro tests with tiaprofenic acid, which showed that with Zimmerman reagent it produced a chromogen with a broad peak of absorbance (maximum at 550 nm); dehydroepiandrosterone and other androgens produce a maximum at 515 nm (Gray et al, 1969). The normal suppression of urine cortisol by dexamethasone (Liddle, 1960) confirms that the drug is interfering directly in the oxosteroid assay and is not affecting the pituitary-adrenal axis.…”

“…The sodium borohydride used in the first step of the oxogenic steroid assay (Gray et al, 1969) reduces these propionic acid derivatives so that they no longer can react with Zimmerman reagent. Thus the oxogenic steroid result will be unaffected provided that an adequate excess of sodium borohydride is used.…”

“…The assay involves the formation of a chromogen with 17-oxosteroids by the Zimmerman reaction (Callow et al, 1938). Although a number of drugs are known to interfere with this reaction (Varley et al, 1976;Gray et al, 1969) interference by propionic acid derivatives has not been reported. We report here a patient in whom tiaprofenic acid (Surgam TM), a new anti-arthritic propionic acid derivative, was shown to interfere directly in this reaction.…”

Steroid Hormones

“…The M.R.C. Clinical Endocrinology Committee therefore at intervals investigates and publishes analytical methods for steroids, and recently they have carried out an appraisal of a method for urinary 17-hydroxycorticosteroids (Gray et al, 1969). The published performance data are useful to the clinical biochemist who can compare results in his own laboratory, and can ascertain what degree of reliability he can expect from the method.…”