Application of a tissue receptor assay to measurement of serum follitropin (FSH).
A rat testes tubule receptor assay, employing 125I-hFSH as the radioligand, has been applied to measurement of human serum follitropin (FSH). Highly purified hFSH LER-1575C was used as the reference preparation. Problems related to interference with uptake of radioligand by receptor, presumably due to non-hormonal serum factors, were minimized by dialysis of the serum prior to TRA. Results obtained by TRA were compared with those obtained by radioimmunoassay (RIA). The mean index of discrimination (TRA/RIA) for a series of 11 postmenopausal sera (PM) was 5.4 and the mean index of precision was 0.063. Sensitivity of the TRA was 9 ng hFSH/ml. Postmenopausal serum averaged 81 ng/ml, PM on estrogen therapy averaged less than 9 ng/ml, Turners Syndrome was 40 ng/ml. No FSH was detected in hypophysectomized serum, in normal male serum or in blood bank serum. PM levels by TRA were similar to those obtained by others with RIA after multiplying by the conversion factor of 5.4.
D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood*; D006801:Humans; D008297:Male; D008593:Menopause; D011863:Radioimmunoassay; D011869:Radioligand Assay
D005640:Follicle Stimulating Hormone