|
Assay of glycoprotein hormones have wide and numerous applications in research of human reproduction and clinical practice. Because it is cheaper, easier to replicate, and more sensitive, immunoassay is rapidly replacing bioassay for these human hormones in research and in clinical practice. Radiommunoassay varies widely in their degree of specificity for different molecular forms, so the specificity of assay systmes for each hormone should be rigorously assessed. The problem is especially complex with the glycoprotein hormones because of their close structural similarity . Recent researches reveal that the a-subunit, comprising about half the molecule of pituitary FSH, TSH, LH and hCG are very similar to each other for these hormones. Hence one method might be the use of a specific antiserum to the B-subunit of hCG, which would react with both the B-subunit and intact hCG, but not with LH. 1. Binding of 125I-hCG after iodination with anti hCG serum were 23.34+-1.62% at the 3rd week, 13.66+-1.02% at the 4th week, and 6.90+-1.11% at the 6th week. 2. In the displacement study of 125 I-hCG unlabelled hormones from anti-hLH and anti-hTSH sera native hCG cross-reacted with both antisera. 3. Antisera to the B-subunit of hCG discriminated hCG from hLH and hMG while most of antisera produced by immunization with intact hCG did not. 4. None of glycoprotein hormones preparation tested cross reacted at physiological levels in the patients by the hCG B-subunit radioimmunoassay system. The development of that radioimmunoassay and some applications will reflect the potential clinical usefulness of the specific hCG radioimmunoassay.
|