The Prolactin Response to TRH and Domperidone Does Not Differentiate Male Hypothalamic Hypogonadism and Constitutional Delay of Puberty

Summary

In order to test whether prolactin response to challenge with TRH and domperidone, dopamine receptor antagonist, is diagnostic for idiopathic hypothalamic hypogonadism (1HH) we studied 8 normal controls, 9 subjects with delayed sexual development and 6 patients with IHH TRH test (200 μg i.v. holus) and dompericlone (10 mg i.v. bolus) were given on two different days. Prolactin (RIA-Biodata) was determined in blood samples during the test. The basal value of prolactin in subjects with delayed puberty and healthy controls did not differ from basal values of prolactin in patients with IHR. The peak elevation of prolactin after TRH in subjects with delayed puberty and healthy controls did not differ from that in patients with 1HH. After successful treatment of one patient with 1HH (Kallmann's syndrome) with pulsatile s.c. LHRH we did not find any change in the response of prolactin to TRH challenge after 1, 3 and 6 months of treatment, while prolactin response to domperidone increased. Prolactin responses to TRH and domperidone are not differential for the early diagnosis of 1HH. Successful treatment of a patient with 1HH did not change the response of prolactin to TRH, but increased prolactin response to domperidone possibly due to altered steroid milieu.

Key words

Hypothalamic hypogonadism - Delayed puberty - Prolactin - TRH - Domperidone