Urinary glucocorticoid excretion.

Abstract

In recent years two comparatively simple methods have been described for the assessment of urinary glucocorticoid excretion. Reddy, Jenkins, and Thorn in 1952 gave details of a method for estimating urinary 17-hydroxycorticoids. This involved extraction of the urinary glucocorticoids (cortisone and hydrocortisone) and their metabolites with n-butyl alcohol and the use of the Porter-Silber colour reaction. The second method is the measurement of urinary 17-ketogenic steroids (Norymberski, Stubbs, and West, 1953). This is done by oxidizing the glucocorticoids and their metabolites to 17-ketosteroids with sodium bismuthate and estimating the newly formed and pre-existing 17-ketosteroids by the Zimmermann reaction. If at the same time the 17-ketosteroid content of the untreated urine is measured, the increase following bismuthate oxidation is an index of the glucocorticoid content of the urine. For the investigation of patients suspected of having adrenal dysfunction, it would be of considerable value if the urinary glucocorticoid content could be assessed by a method suitable for use in a hospital biochemical laboratory. From the original descriptions of these methods either appears suitable for this purpose. We have used them in the investigation of patients with endocrine disease, after adrenalectomy and in other connexions, and have encountered certain difficulties. This has led us to modify the original Norymberski method and to adopt some of the features of the urinary 17-hydroxycorticoid estimation described by Smith, Mellinger, and Patti (1954). Using these modifications we have tried to ascertain whether these methods really are an index of urinary glucocorticoid excretion. The 17-hydroxycorticoid and 17-ketogenic steroid content of more than 400 urines have been measured and the results compared. Recoveries of cortisone and hydrocortisone added to urine have been studied and the glucocorticoid excretion of adrenalectomized patients receiving different amounts of hydrocortisone and of cortisone acetate have been measured. URINARY 17-HYDROXYCORTICOIDS The first difficulty encountered with this method was in the purification of n-butyl alcohol. The methods suggested by Reddy (1954) and Smith et al. (1954) proved disappointing. We are indebted to Mr. R. W. H. Edwards, B.Sc., of the Courtauld Institute of Biochemistry of the Middlesex Hospital, for suggesting the method described in the next section. The other difficulty was with the Porter-Silber reaction. 17, 21-Dihydroxy-20-ketosteroids produce a yellow colour with phenylhydrazine and strong sulphuric acid, but when the reaction is applied to urine extracts allowance must be made for the colour produced by strong sulphuric acid without phenylhydrazine. Like Smith et al. (1954) we found that the 62% sulphuric acid used in the original method gave very high readings; their modification using 56% sulphuric acid and allowing longer time for the colour to develop has proved more satisfactory.