Abstract
Estriol antisera were raised and studied for the use in radioimmunoassay (RIA) of urinary estrogen as an aid of diagnosis of feto-placental function. Antisera to estriol-related six haptens, i.e., estriol 16-glucuronide (E3-16-G), estriol 16-hemisuccinate (E3-16-succ), estriol 17-hemisuccinate (E3-17-succ), estriol 16, 17-dihemisuccinate (E3-16, 17-succ), estriol 3-carboxymethylether (E3-3-CME) and estriol 3-glucuronide (E3-3-G), were obtained by immunizing rabbits with the respective haptenbovine serum albumin (BSA) conjugate. Antiserum to E3-16-G-BSA reacted significantly with E3-16-G, C-17 conjugated estrogens and free estrogens. But it did not react with C-3 conjugated estrogens and other steroids. Similar properties were observed with antisera to E3-16-succ-BSA, E3-17-succ-BSA and E3-16, 17-succ-BSA, but their reactivities with C-16 or C-17 conjugated estrogens were slightly lower than that of anti-E3-16-G-BSA serum. Among antisera which were raised against estriol linked to BSA via hemisuccinate varying in linking posirion, anti-E3-16-succ-BSA serum highly reacted with E3-16-G, while anti-E3-17-succ-BSA did with E3-17-G. Anti-E3-16, 17-succ-BSA serum reacted with C-16 and C-17 conjugated estrogens to nearly the same extent. Antisera to both E3-3-CME-BSA and E3-3-G-BSA reacted with estrogens conjugated at C-3 position, but failed to react with C-16 or C-17 conjugated estrogens. The latter antiserum reacted more specifically with E3 and E3 3-G than the former. Estrogen values in pregnancy urine samples estimated by the RIA by use of anti-E3-16-G serum were not influenced by other components in urine, and showed a good correlation of y=0.81x-1.28, r=0.983 with those determined by the currently available colorimetric method with E3-kit.
