Abstract
We produced experim entalautoimmune hypophysitis (EAH) in rats and investi gated its characteristics. Female Lewis rats were immunized by two injections with homologous pituitary homogenate and complete Freund’s adjuvant. Blood was coll ected seri ally from the rats, and serum antibodies to pituitary antigens were examined . The rats were sacrificed 2 or 4 weeks after the final immunization, and hi stological examinations of the endocrineorgans were carried out. Hi stolog ical examination revealedslight , focal infiltration of mononuclearcells in the pituitary gland only in the rats immunized with the pituitary homogenate. Infiltration of mononuclearcells was not observed in the thyroidgland , pancreas, adrenal gland , or ovary. In the serological examination, antibodies to bothcytoso licantigens and cytoplas micparticle a nti gens from the pituitaryg land were detected by enzyme- linked immunosorbent assay (ELISA), and these antibody levels increased with time. We stern blottingusing the sennn antibodiesidentified an immunoreactive protein of -2 1.5 k.Daamo ng these antigens, and we confirmed that this protein was ratgrow thhormone (GH). Furth ermore, antibodies to GH, thyrotropin (TSH), and luteinizing hormone (LH) were detected by E LISA. Antibodies to folli cule stimulating horm one, prol actin , or adrenocorticotropin were not detected . These data suggest that several antigens from the pituitary gland are involved in EAH inrats, and that GH, TSH, and LH are major antigens among the pituitary antigens in this model.