Pituitary Responsiveness

Excerpt

To the editor: I read with great interest the recent paper by Samaan and associates, "Hypopituitarism After External Irradiation" (Ann Intern Med 83:771-777, 1975); I question, however, one important conclusion reached from the reported data. The existence of primary pituitary damage secondary to irradiation was based on finding unresponsive pituitary thyrotrophins and gonadotrophins to single doses of thyrotrophin-releasing hormone (TRH) and luteinizing-releasing hormone (LH-RH), respectively. Yoshimoto, Moridera, and Imura (1) have shown that prolonged stimulation of pituitary gonadotrophins by LH-RH was necessary to restore pituitary responsiveness in several patients with isolated gonadotrophin deficiency, anorexia nervosa, and miscellaneous organic hypothalamopituitary lesions.