A Diurnal Rhythm in the Excretion of Neutral Reducing Lipids by Man and Its Relation to the 17-Ketosteroid Rhythm*

Abstract

T HE observation that there is a diurnal rhythm in urinary ketosteroid excretion (1,2,3) and that this may be related to stress-stimulated adrenocortical secretion (2) led us to examine other possible indices of adrenocortical secretion. The development of a method for measuring neutral reducing lipid in urine by Heard and Sobel (4) and the indications that this material represents in large part corticosteroid possessing reducing activity by virtue of its a-ketol sidechain (4, 5, 6), offered an opportunity to assess the diurnal changes in excretion of adrenocortical substances, which are entirely different from those of the 17-ketosteroids. MATERIAL AND METHODSTwenty-four normal healthy men ranging in age from 24 to 72 years (see Table 1) were the subjects of this investigation. Urine was collected over a 24-hour period in three lots covering approximately the periods 11 p.m. to 7 a.m. (sleep), 7 a.m. to 11 a.m. (morning) and 11 a.m. to 11 p.m. (day).From an aliquot of each collection, fractionation for the neutral ketones and 17-ketosteroid determination was made by methods previously described (7). A second aliquot wasemployed for determining neutral reducing lipid by the Heard-Sobel method (4). In our experience the urine of normal men ordinarily contains sufficient 17-ketosteroid and neutral reducing lipid to make the equivalent of a half-hour collection sufficient for accurate colorimetric determination. Creatinine determinations were made routinely on each specimen (7). RESULTSIn Table 1 we present for each subject the urinary outputs of neutral reducing lipid and 17-ketosteroid respectively, on the basis of mg. per

The Normal Levels of 17-Hydroxycorticosteroids in the Peripheral Blood of Man 1

“…Late evening levels remained low. This is consistent with the data of Pincus, Hoagland, Romanoff, and Carlo (12,13), who found comparable changes in the diurnal excretion of 17-ketosteroids and neutral reducing lipids in the urine, as well as those of Sandberg and his co-workers (14), who observed the same pattern in the urinary 17-hydroxycorticosteroids following glucuronidase hydrolysis. Both groups recorded the highest urinary levels in the morning.…”

Diurnal Variation in the Urinary Excretion of Neutral Lipid-Soluble Reducing Steroids in Congestive Cardiac Failure and Cirrhosis of the Liver With Ascites 12

“…The average 24-hour excretion of steroids, 3.32 milligrams, is slightly higher than for the other two groups. However, these differences are not statistically significant.…”

A Study of Pituitary-Adrenocortical Function in Normal and Psychotic Men

“…Since the reaction to sugar seems to operate by pituitary activation (4) there is implied the secretion of more than one adrenocorticotrophin. Such a possibility has been suggested before (31,37), and presumably our ACTH preparations concentrate both mineralocorticoid and gluco-corticoid trophins.…”