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Determination of the urinary excretion of 1 7-ketosteroids (17-oxosteroids) is the most important laboratory test in the investigation of endocrine disorders involving the adrenal cortex and gonads in children. The normal range of excretion varies with the method employed, since non-steroidal pigment may to a greater or lesser degree be measured as 17-ketosteroid. It is important therefore to know the normal range for the method used. This applies particularly to children, in whom excretion rises with age. In this paper normal values for the two most commonly used methods are given as well as figures for the commoner pathological conditions in which 17-ketosteroid excretion is raised. The evaluation of 17-ketosteroid excretion in pathological disorders is discussed. MethodsExtraction. Twenty-four-hour urines from 73 normal children were extracted as follows. After the volume of the specimen had been measured, 100 ml. were brought to the boil on a hot-plate, and 15-0 ml. of concentrated hydrochloric acid poured down the reflux condenser. Boiling was continued for exactly 10 minutes. The urine was then cooled under the tap and extracted with 2 x 75 ml. and I x 50 ml. of ether. The ether extract was washed with 2 x 15 ml. of 10% sodium hydroxide, I x 10 ml. of a saturated solution of sodium hydrosulphite and then with water until the aqueous layer was neutral to litmus. After draining off all the water the ether was dried by adding a little anhydrous sodium sulphate and swirling. The ether was filtered (glass wool) and evaporated on a water bath using an air leak. Extracts were desiccated overnight. Each extract was then dissolved in 2-0 ml. of absolute alcohol and aliquots of 0-20 ml. removed for estimation.Methods of Estimation. Method 1. Four tubes were set up. The first contained 0 2 ml. of extract, 0-2 ml. of 2-0% m-dinitrobenzene and 0 1 ml. of 5 0 N. aqueous potassium hydroxide; in the second tube 0-2 ml. of absolute alcohol was substituted for m-dinitrobenzene (=control); in the third tube 0-2 ml. of absolute alcohol was substituted for the extract (=reagent blank); in the fourth tube 0*2 ml. of absolute alcohol containing 50 jig. dehydroepiandrosterone was substituted for the extract. The tubes were incubated in a water bath at 25 -00 02°C. for 60 minutes in the dark and then to each tube was added 10-0 ml. of 70% ethanol. Readings were made in the Spekker (Hilger absorptiometer) using filter 604 and 70% alcohol as blank. Control and reagent blanks were subtracted from the reading. The amount of 1 7-ketosteroid present in the test was calculated by comparison with the standard reading (fourth tube) and the total for the 24-hour urine derived from this. This method of estimation has been in routine use in this hospital for many years and is similar to that of Holtorff and Koch (1940).Method 2. In this method of estimation, which employs alcoholic in place of aqueous potassium hydroxide, the correction factor of Talbot, Berman and MacLachlan (1942) recommended by the Medical Research Council (1951) was used....

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