The binding of 125I-TSH to thyroid cell receptors previously deformed (in neonatal age) by gonadotropin treatment.

Single gonadotropin treatment of newborn rats caused a 63-71% decrease of TSH-binding on isolated thyroid cells prepared from thyroid glands of both 6- and 13-month-old animals. This fact points out that: (1) in newborn animals the hormone receptors are still plastic and deformable and (2) the damaging effect of the analogous hormone manifests itself at the receptor level.