We have studied the concentrations of intact human choriogonadotropin (hCG) and the free hCG beta-subunit in blood samples from singleton pregnancies at risk for habitual or threatened abortion. The samples were obtained weekly between the 6th and 12th weeks and in the 14th and 16th weeks of gestational age. The concentrations of intact hCG, of the free hCG beta-subunit, and of "total" hCG (i.e...

BACKGROUND The pregnancy hormone human chorionic gonadotropin (hCG) and its free subunits (hCG alpha, hCG beta) are produced in the male reproductive tract and found in high concentrations in seminal fluid, in particular hCG alpha. This study aimed to elucidate changes in peptide hormone profiles in patients showing abnormal semen analyses and to determine the genuineness of the highly abundant...

Human chorionic gonadotropin (hCG) is a dimeric glycoprotein hormone consisting of noncovalently associated and subunits. It is produced principally by the trophoblastic cells of the placenta but may also be produced by nontrophoblastic tissues including normal pituitary and neoplastic cells. Therefore, qualitative and quantitative measurement of hCG is clinically useful in the diagnosis of nor...

A multiple enzyme immunoassay (multi-EIA) was developed to quantify whole-molecule human choriogonadotropin (w-hCG) and free hCG beta-subunits (hCG-beta) simultaneously. A clone of a specific monoclonal antibody was coupled to solid phase; two other clones of different monoclonal antibodies were conjugated to horseradish peroxidase (HRP; EC 1.11.1.7) and alkaline phosphatase (AP; EC 3.1.3.1), r...

Concentrations of human choriogonadotropin (hCG) and its free beta subunit (beta hCG) were measured in serum by highly sensitive and specific time-resolved immunofluorometric assays (IFMAS). The results were confirmed by completely separating beta hCG and hCG by a novel method based on hydrophobic-interaction chromatography. We used three monoclonal antibodies in two different combinations. In ...

The synthesis of human chorionic gonadotropin (HCG) and its subunits was studied in simian virus 40 (SV40) tsA mutant-transformed human first-trimester and term placental cells at 33 degrees (the temperature at which the cells have the transformed phenotype) and at 40 degrees (the temperature at which the tsA transformants regain their nontransformed phenotype). 8-Bromo cyclic adenosine 3':5'-m...

Hyperglycosylated hCG (hCG-H) is a glycosylation variant of the hormone hCG. Here we review all that is known about this independently functioning molecule. As discussed, it is a very different molecule to the hormone hCG. First, hCG-H is produced by cytotrophoblast cells while regular hCG is made in syncytiotrophoblast cell. Second, it is an autocrine acting directly on the cells which produce...

In biological fluids, hCG and its free alpha- (hCG alpha) and beta-subunits (hCG beta), occur in multiple forms. These various forms differ at the molecular level primarily in glycosylation, but also differ in protein backbone modifications corresponding to the urinary low molecular weight fragment of the hCG beta-subunit (beta-core fragment). This microheterogeneous nature can be demonstrated ...

The pregnancy hormone human chorionic gonadotropin (hCG) is also present at low concentrations in plasma and urine of men and nonpregnant women. hCG immunoreactivity occurs in various molecular forms: Besides the intact hCG heterodimer, considerable amounts of proteolytically cleaved forms, free subunits, and fragments are found in plasma and urine. Especially in urine, proteolytic fragments co...

A photoaffinity derivative of human chorionic gonadotropin (hCG-N-hydroxysuccinimidyl-4-azidobenzoate (hCG-HSAB) ) was used to identify components of the lutropin (LH)/hCG receptor in plasma membranes prepared from pregnant mare serum-pretreated rat ovaries. In intact plasma membranes, the Kd for hCG (1 X 10(-10) M) was the same with both 125I-hCG and 125I-hCG-HSAB, and the binding capacity for...