The capacity of iodotyrosines and iodothyronine analogues to displace tracer[125I] L-3,5,3′ triiodothyronine from specific nuclear binding sites in rat liver and heart was related to the displacement capacity of nonradioactive triiodothyronine. Iodotyrosines and L-3,3′,5′ triiodothyronine ("reverse T3") were devoid of displacement activity. Analogues with 3,5 substitution in the "inner" ring and single "bulk" substitution in the 3′ position in the phenolic ring exhibited the strongest displacement activity. When the distribution, fractional removal rates and metabolic conversion of the analogues were taken into account, displacement activity appeared to correlate well with the reported thyromimetic activity. These results support the biologic relevance of the nuclear sites.
|Original language||English (US)|
|Number of pages||7|
|Journal||Biochemical and Biophysical Research Communications|
|Publication status||Published - Dec 10 1973|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology