Abstract
Data is presented on the bioneutralization capacity per unit immunoactivity of 30 serum samples of women immunized with the .beta.-subunit of human chorionic gonadotropin (.beta.-hCG) or .beta.-hCG associated noncovalently with the .alpha.-subunit of ovine luteinizing hormone (.alpha.-oLH), to form a heterospecies dimer (HSD), which were linked to carriers. The bioassays utilized were inhibition of radioiodinated hCG binding to rat testicular receptors in vitro and the inhibition of hCG induced testosterone production in mice. In both assays, antisera of women immunized with the HSD had a bioactivity to immunoactivity ratio that was about 25% higher, on an average, than antisera of women immunized with .beta.-hCG, suggesting a better bioneutralization capacity of sera raised by the HSD in women.