Immunoperoxidase staining of primate pituitaries with antibodies against the beta subunits of human pituitary glycoprotein hormones.

The immunocytochemical specificity of antibodies against the beta subunits of human pituitary glycoprotein hormones was tested on human and monkey hypophyses. Anti-luteinizing hormone (LH) beta stained only gonadotrophic cells in both species, and anti-thyroid-stimulating hormone (TSH) beta only thyrotrophic cells. In monkeys, anti-follicle-stimulating hormone (FSH) beta demonstrated only gonadotrophs, but in man the antibody stained thyrotrophs equally well. Staining of the two cell types was diminished to a similar degree by dilution of the anti-FSH beta antibody. Human gonadotroph heterogeneity was revealed by absorption of anti-FSH beta with LH beta or TSH beta, which abolished immunostaining of a subset of gonadotrophs. Limitations in the immunocytochemical specificity of antibodies against beta subunits of pituitary glycoprotein hormones may be a consequence of incomplete purity of the generating antigens, structural overlap among the beta subunit of the three hormones, or a combination of these.