Low TRH-TSH responses in human essential hypertension.

Thirty female and male essential hypertensive patients and eighteen normotensive controls were submitted to the TRH-TSH conventional test (200 ug intravenously, bolus injection of TRH). Supramaximal doses of 400 and 600 ug were repeated with a week interval to each subject. Hypertensives showed a significant lower response to both conventional and supramaximal TRH doses. Hypothalamic-pituitary-thyroid axis abnormalities, secondary to TRH-receptor alterations, could account for this result.