Chromatographic separation of the sodium-retaining corticoid from the urine of children with nephrosis, compared with observations on normal children.

Previous studies in this laboratory have indicated that a high degree of sodium-retaining activity may be present in chloroform extracts of urine of certain patients with edema (2-6). When patients with the nephrotic syndrome are treated with ACTH or cortisone, the increased excretion of sodium in the urine is associated with a reduction in the sodium-retaining activity of the lipid extract (4, 5). Comparable extracts of urine of normal children or adults show slight activity and may even promote the excretion of sodium in the bioassay used. When the dietary intake of sodium is decreased, a moderate increase in sodium-retaining activity of the urine extract may be observed. These findings suggest that the sodium-retaining activity of the lipid extract may reflect a stimulus to conserve sodium. Further studies of the origin, regulation, and function of the observed sodium-retaining activity require more definitive study of the material responsible for this biological activity. Some observations on fractionation of active extracts by displacement chromatography (7) and by paper partition chromatography have indicated that the sodium-retaining activity is due to an unidentified corticoid which contains more oxygen than desoxycorticosterone (6). Systematic analysis of highly active extracts by chromatography was therefore undertaken to ob-