The incidence of anti-zona activity in post-menopausal women

Forty sera from post-menopausal women were tested for the presence of anti-zona pellucida antibodies by an immunofluorescence method. Twenty sera showed positive fluorescence on the surface of cumulus-free porcine oocytes. In a control group of 22 female blood-donors of reproductive age, only three sera gave positive fluorescence. In all the above mentioned positive sera the anti-zona antibodies could be absorbed with porcine erythrocytes. This was, however, not the case when rabbit anti-porcine zona pellucida sera were used instead of the human sera. This would suggest that porcine erythrocytes and human zonae pellucidae share common antigenic determinants.