Biological and immunological activity of human chorionic gonadotrophin in maternal serum during early pregnancy.
Serum chorionic gonadotrophin (hCG) levels were measured by three different assay methods in 20 women admitted to legal abortion and 21 patients having insulin-dependent diabetes, both during 8 to 14 weeks of pregnancy. Biological activity of hCG was determined with a mouse Leydig cell in-vitro bioassay, binding activity of the hormone to LH receptors by rat testis radioreceptorassay, and immunoreactivity by fluorimmunoassay. Bioassay and radioreceptorassay gave 1.4 and 1.7-fold higher hCG concentrations than fluoroimmunoassay using the same standard. Correlations between hCG levels measured by bioassay and fluoroimmunoassay (r = 0.81; P less than 0.01) and radioreceptorassay and fluoroimmunoassay (r = 0.95; P less than 0.01) were good. The results emphasize the heterogeneity of hCG in the pregnancy serum. Different domains of the molecules are recognized by assay methods based on antigenicity, receptor binding and biopotency of the hormone.
Ranta
T
T
Department of Obstetrics and Gynaecology, Päijät-Häme Central Hospital, Lahti, Finland.
Ylinen
K
K
Stenman
U H
UH
Nikula
H
H
Huhtaniemi
I
I
D000328:Adult; D001681:Biological Assay; D006063:Chorionic Gonadotropin / Q000097:blood*; D005260:Female; D006801:Humans; D007118:Immunoassay; D011247:Pregnancy / Q000097:blood*; D011261:Pregnancy Trimester, First; D011254:Pregnancy in Diabetics / Q000097:blood*
D006063:Chorionic Gonadotropin