[Thyrotropin receptor is expressed in non-thyroid tissues].

We have obtained TSH-R cDNA fragments from rat retro-orbital tissues and adipose tissue as well as FRTL5 cells by polymerase chain reaction methods. Nucleotide sequence of the non-thyroid cDNA was identical to that of the thyroid. Northern blot analysis has revealed that extremely high amount of TSH-R mRNA exist in the adipose tissue. TSH-R peptide antibody produced in rabbit, which stained recombinant TSH-R as 104 and 100 kDa proteins, also recognized the same M.W. bands in the adipose tissue and the retro-orbital tissues. These results suggest that TSH-R is expressed even in non-thyroid tissues.