Monoclonal antibody LICR-LON-E36 recognizes gonadotrophs in female rat pituitaries

The distribution of the antigen localized by monoclonal antibody LICR-LON-E36 has been studied by means of light and electron microscopical immunocytochemical procedures on resin-embedded pituitaries from male and female rats. Using both immunoperoxidase and immunogold labeling techniques, the localization of LICR-LON-E36 has been compared with that obtained with antibodies against the beta subunit of rat luteinizing hormone (beta LH) and human follicle stimulating hormone (beta FSH), porcine adrenocroticotropic hormone (ACTH) and rat S-100. LICR-LON-E36 is localized in a portion of beta LH-containing cells in female rat pituitaries and where present both antigens are localized within the same storage granules. LICR-LON-E36 is rarely detectable within beta LH-containing cells of male rat pituitaries that also stain positively with anti-beta FSH antibodies. ACTH and S-100 were localized within different cell populations.