THYROTROPIN RECEPTOR IN NONTHYROID TISSUES

Thyrotropin receptor (TSR-H), the main target for the autoantibody in Graves′ disease, has been thought to be a thyroid-specific protein. However, we successfully obtained the cDNA fragments of TSR-H from rat retro-orbital tissues and adipose tissues by using polymerase chain reaction methods. Sequencing has revealed that the nucleotide sequence of the cDNA5 from these non-thyroid tissues was identical to that from the thyroid. TSH-R peptide antibody, which recognizes rat TSH-R, stained a 104 kDa protein from the retro-orbital tissues and the adipose tissues. The band was not detected with the antibody preabsorbed with the peptide. These results suggest that the message is translated to make a TSR-H protein even in these non-thyroid tissues. © 1993 Academic Press, Inc.