Antiidiotypic antibody to gonadotropin releasing hormone as probe for cell surface receptors

Monoclonal antibodies were raised to the idiotype of a gonadotropin releasing hormone (GnRH) specific antibody, one of which was found to bind specifically to GnRH receptors present on pituitary gonadotrophs, placental syncytiotrophoblasts and testicular Leydig cells. These observations were confirmed by Western and ligand blotting as well as by the ability of the antibody to induce an increase in intracellular Ca++ in a mouse gonadotroph cell-line viz., alpha T3-1