| Porter-Silber chromogens test | A test, dependent on the Porter-Silber reaction, that is used as a measure of adrenocortical function and is performed on urine. Low values are seen in Addison's disease and hypopituitarism; high values are seen in Cushing's syndrome and extreme stress. Synonym: 17-OH-corticoids test, Porter-Silber chromogens test. (05 Mar 2000) |
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| chromogen | 1. A substance, itself without definite colour, that may be transformed into a pigment; denoting especially benzene and its homologues toluene, xylene, quinone, naphthalene, and anthracene, from which the aniline dyes are manufactured. 2. A microorganism that produces pigment. Porter-Silber chromogens, yellow phenylhydrazones formed by the reaction of 17,21-dihydroxy-20-oxosteroids with a phenylhydrazine-ethanol-sulfuric acid reagent; used chiefly to determine plasma cortisol concentrations and the urinary output of 17-hydroxycorticoids. (05 Mar 2000) |
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