Inhibition of thyrotropin (TSH) release by chronic treatment with small quantities of triiodothyronine (T3) and thyroxine (T4) was evaluated by determining the serum TSH response to thyrotropin-releasing hormone (TRH) in normal subjects and hypothyroid patients. Response to TRH was determined before treatment and after each dosage of a synthetic combination of T3 + T4 had been given for 3-4 wk.
Peter J. Snyder, Robert D. Utiger