60 (after menopause) glycoprotein hormones
(ImU/ml) Table 3.
Cross-reactivity with other glycoprotein hormones
was studied by use of luteinizing hormone, follicle-stimulating hormone, and TSH (all from Scripps Laboratories).
hCG was thus considered a suitable model for standardization of glycoprotein hormones
in general (5).
hCG, in common with other glycoprotein hormones
, is characterized by sugar moieties on both subunits that determine receptor affinity and metabolic clearance.
This implies that a slow and specific mechanism exists for the removal, deactivation, and degradation of the glycoprotein hormones
Because the same degradation process is likely to act on both hCG[beta] and LH[beta] (and most probably FSH[beta] and TSH[beta]) the resulting core-defining epitopes would be common to all glycoprotein hormone
urinary [beta]-core molecules (19, 27).
The legislation, if enacted, would cover three hard drug categories: anabolic androgenic steroids, Beta 2 agonists (other than asthma medications) and peptides and glycoprotein hormones
and analogues, which include growth hormones and erythropoeitin.
Follicle-stimulating hormone (FSH) is a member of the glycoprotein hormones
synthesized and secreted by gonadotropes in the anterior pituitary gland and is comprised of two dissimilar subunits, alpha and beta, encoded by separate genes (Jameson et al.
Indeed, circulating insulin is homogeneous, unlike glycoprotein hormones
(such as human chorionic gonadotropin, luteinizing hormone, and follicle-stimulating hormone), for which immunoassay standardization is problematic (12).
Trophogen's unique protein engineering platform technology allows design of more potent and efficacious analogs of glycoprotein hormones
and related growth factors to address several large therapeutic markets including infertility.
However, interference is rare in assays for pituitary glycoprotein hormones
, being described only for thyroid-stimulating hormone (4, 5).
We report on our experience on the analytically, and in some cases clinically, significant inaccuracy of tests for three of the most commonly requested analytes, namely the pituitary glycoprotein hormones
thyroid-stimulating hormone (TSH) 3 luteinizing hormone (LH), and follicle-stimulating hormone (FSH), in 5310 patients.
These can be sub-classified into the following six categories: Adrenergic, Dopaminergic, Opioid, Sensory (rhodopsin--olfactory, taste), Glycoprotein hormones
, Lipids, Small Peptides.
The degree of glycosylation, particularly terminal sialylation, has been shown to affect the in vivo and in vitro bioactivities of TSH (6,16),but variations in glycosylation can also influence iiiitnunoreactivity, as discussed for the glycoprotein hormones
in general (17) and TSH in particular (18).
We further stimulated T-47D cells with the glycoprotein hormones
LH, FSH, and hCG and with prolactin and growth hormone.