A STUDY OF THE IMMUNOLOGICAL DETERMINATION OF PITUITARY GONADOTROPHIN IN URINE

Abstract

An antiserum to chorionic gonadotrophin (HCG) has been studied in agar diffusion, hemagglutination and hemagglutination inhibition experiments. The anti-HCG serum contained antibodies to inert urinary proteins and serum proteins as well as a hormone-specific antibody. Absorption of the anti-HCG serum with small amounts of inert urinary protein removed precipitins to non-hormonal protein, without altering the hemagglutinating titer of the antiserum. There was no difference between absorbed and unabsorbed anti-HCG serum in hemagglutination inhibition reactions with inert and gonadotrophic urinary extracts. When larger amounts of inert protein were used for absorption there was a fall in the hemagglutinating titer of the anti-serum but it was shown that this was due to removal of hormone specific antibodies. Urinary extracts were obtained from patients with various endocrine disorder, from patients with normal pituitary and gonadal function and from menopausal subjects. The results of bioassay and immunoassay of these extracts were compared. It was found that many of the extracts, although potent in the immunoassay, were biologically inactive. It is concluded that a specific or non-specific reaction can occur between nonhormonal urinary proteins and the antihormone. The anti-HCG serum used in the present investigation, although successfully used for pregnancy diagnosis and HCG assay, was unsuitable for urinary gonado-tropin estimation in non-pregnant individuals.