Effect of Triiodothyronine Administration on the Plasma TSH and Prolactin Responses to TRH in Patients with Hypothalamic-Pituitary Insufficiency

Publisher Website
Google Scholar
Abstract
A study was carried out in 10 patients with multiple pituitary hormone deficiencies to determine the response of thyroid-stimulating hormone (TSH) and prolactin (PRL) to thyrotropin-releasing hormone (TRH) and their suppressibility by treatment with triidothyronine (T3) given at a dose of 60 .mu.g/day for 1 wk. In 3 patients the basal TSH values were normal and in 7 patients, 2 of whom had not received regular thyroid replacement therapy, they were elevated. The response of TSH to TRH was normal in 6 patients and exaggerated in 4 (of these, 1 patient had not received previous substitution therapy and 2 had received only irregular treatment). The basal and stimulated levels of TSH were markedly suppressed by the treatment with T3. The basal PRL levels were normal in 7 and slightly elevated in 3 patients. The response of PRL to TRH stimulation was exaggerated in 2, normal in 6 and absent in 2 patients. The basal PRL levels were not suppressible by T3 treatment but in 4 patients this treatment reduced the PRL response to TRH stimulation. T3 suppresses TSH at the pituitary level and the hyperreactivity of TSH to TRH and the low set point of suppressibility are probably due to a lack of TRH in the type of patients studied.

This publication has 1 reference indexed in Scilit: