THE LEVELS OF 17-HYDROXYCORTICOSTEROIDS IN PERIPHERAL BLOOD OF HUMAN SUBJECTS*†

Abstract

BY USE of the method of blood analysis for 17-hydroxycorticosteroids described by Nelson and Samuels (1) it has been possible to measure levels of these corticosteroids in the peripheral arterial and venous blood of a number of human subjects. Although adrenal responsiveness has been estimated by such techniques as eosinophil counts and urinary excretion of steroids, no previous direct measurements of the levels of cortical hormone in peripheral blood have given quantitative results. The biologic assay methods (2, 3) which have been applied either lack sufficient sensitivity or have large probable errors. The chemical methods used by others (4) have been nonspecific, resulting in considerable overestimation when applied to the crude extracts which have been used. Samples of approximately 30 ml. of blood were drawn and immediately placed in small bottles containing 3 mg. of heparin. Samples were refrigerated and the steroid determinations were run the same or the following day whenever possible. Occasional samples were held as long as three days. To check the stability of the compound, samples of the same blood were analyzed at intervals over a period of seven days. No significant variation in the results of the analysis occurred. It seems highly improbable, therefore, that any error could have been introduced because of the time during which any sample was held.