Nocturnal Secretory Patterns of FSH, GH, LH and TSH

Abstract

The nocturnal secretory patterns of follicle-stimulating hormone (FSH), growth hormone (GH), luteinizing hormone (LH) and thyroid-stimulating hormone (TSH) were studied in 1 female and 4 male volunteers. Immunoreactive FSH, GH, LH and TSH in serum were assayed by a radioimmunosorbent technique. Non-conjugated 11-hydroxycorticosteroids in plasma were also measured in the male volunteers by a fluorimetric method. Blood samples were taken half hourly from 10 p.m. to 8 a.m. Polygraphic monitoring of sleep stages was performed. In all the subjects a marked elevation of serum GH occurred within 60 minutes after the onset of sleep and additional, isolated GH peaks were observed in 3 subjects. The serum concentrations of FSH, LH and TSH also fluctuated, but the variations were small compared with the fluctuations of GH. The serum levels of FSH, LH and TSH respectively were not correlated with the depth or stages of sleep. The observed fluctuations, in the serum levels of all hormones assayed, are larger than could be expected from intra-assay errors and probably represent changes in the secretion rate of the hormones. A lack of concordance between the secretory patterns of FSH, GH, LH and TSH indicates that different mechanisms may be involved in their release.