Radioimmunoassay of the anti-cancer agent 4-hydroxyandrostenedione in body fluids.

Antibodies were produced in sheep against a new anti-breast cancer drug 4-hydroxyandrostenedione (4-OHA) using two hapten-ovalbumin conjugates. One of these conjugates (4-hydroxytestosterone-ovalbumin) produced an antiserum suitable for the development of a radioimmunoassay that would allow direct measurement of 4-OHA in plasma at concentrations down to 82 pmol/l, with adequate accuracy, precision and scope for further sensitivity. Although this assay would measure 4-hydroxytestosterone (4-OHT) in addition to 4-OHA, the present data suggest that the magnitude of any interference from endogenous steroids and those derived from 4-OHA could only be minimal.

Serum kinetics of the anti-cancer agent 4-hydroxyandrostenedione in the rat.

A previously described radioimmunoassay (RIA) method for the measurement of 4-hydroxyandrostenedione (4-OHA) was used to investigate the serum drug levels attained after a single oral dose in male and female rats. Marked variability of serum drug concentrations and their time course were evident in male animals at all dose levels. In the female rat, in contrast, serum 4-OHA showed fewer individual differences, rose more rapidly and was sustained at substantially higher concentrations.

Antibodies to 4-hydroxyandrostenedione--a new anti-breast cancer agent suitable for use in a radioimmunoassay.

A specific antiserum suitable for radioimmunoassay (RIA) of 4-hydroxy-4-androstene-3,17 dione (4-OHA) has been developed. Sheep antiserum was raised by injecting two different conjugates prepared by coupling 4-OHA to ovalbumin. Antisera obtained from a sheep immunised with 4-hydroxy-testosterone-17-hemisuccinate ovalbumin conjugate were of higher titre and more specific than antisera obtained from sheep immunised with 4-hydroxyandrostenedione-7 alpha-carboxyethylthioether.