Circulating anti-pituitary antibodies (APAs) have been detected in patients
with autoimmune diseases, although the role of autoantibodies in the patho
genesis of autoimmune diseases is still unclear. With the aim of elucidatin
g the autoimmune mechanisms involved in patients with multiple endocrine di
sorders, we evaluated the pathological changes in the pituitary gland, thyr
oid, pancreas and adrenal gland of mice, both wild-type and using a murine
model of autoimmune thyroid disease [MRL-Ipr/Ipr] that had been immunized w
ith murine, rat, porcine or human pituitary glands. In four of seven mice,
a 22 kD band corresponding to APA was detected by Western blotting in the s
erum from mice that had been immunized with human pituitary tissues but not
in the serum from mice immunized with rat or pig tissue. Inflammatory chan
ges were detected in all groups of mice, occurring in the hypophysis, pancr
eas and adrenal glands but not in the thyroid. In conclusion, APA-induced a
utoimmune endocrine disorders are likely to be important for studying the m
echanisms involved in autoimmune syndromes.