IMMUNOCHEMICAL AND BIOLOGICAL SIMILARITY BETWEEN HUMAN LUTEINIZING HORMONE AND ONE OF THE ANTIGENIC COMPONENTS OF HUMAN CHORIONIC GONADOTROPHIN.

Abstract

ABSTRACT Immunological investigations with human chorionic gonadotrophin (HCG) were carried out in order to characterize the antigens of HCG. Attempts were also made to find out whether HCG has antigens common to those of human luteinizing hormone (LH) and human follicle stimulating hormone (FSH) and also to ovine, bovine and porcine LH and pregnant mare serum gonadotrophin (PMSG). The results of the immunoelectrophoretic analysis carried out have indicated that one of the three antigens of HCG seems to be immunochemically similar to the antigen present in human LH. HCG was not observed to have any antigens in common with ovine, bovine and porcine LH and PMSG as revealed by the tests carried out with antiserum to HCG. The combining power and the biological activity of the antigen common to human LH and HCG were not completely destroyed by heating the hormones at 100° C for 30 minutes. These were, however, destroyed by treating the respective hormones with 30 per cent hydrogen peroxide. Haemorrhagic follicles were observed when human FSH was injected into immature mice together with human LH. Such haemorrhagic follicles were also observed in some of the mice injected simultaneously with heated LH or HCG along with human FSH. The significance of these observations are discussed.