Histamine-induced paradoxical GH response to TRH/GnRH in men and women: dependence on gonadal steroid hormones.
A stimulatory GH response to TRH and GnRH occurs frequently in patients with various pathological conditions, but is absent in normal subjects. We have previously shown that histamine induced a paradoxical GH response to TRH in normal men. Since gonadal steroids influence GH secretion, we investigated whether infusion of histamine might induce a GH response to combined administration of TRH (200 micrograms) and GnRH (100 micrograms) in 6 normal women during the early follicular and luteal phase of the same menstrual cycle and in 7 normal men. Histamine had no effect on basal GH secretion in men or in women during the two phases of the menstrual cycle. However, compared with saline, histamine induced a GH response to TRH/GnRH in men (GH peak: 5.5 +/- 1.0 vs 1.4 +/- 0.3 micrograms/l; p less than 0.01) and in women during the luteal phase (GH peak: 5.2 +/- 1.6 vs 1.5 +/- 0.4 micrograms/l; p less than 0.025), but not during the early follicular phase of the cycle (GH peak: 1.7 +/- 0.5 vs 1.6 +/- 0.3 micrograms/l). In luteal-phase women the GH response to TRH/GnRH correlated with the serum estradiol-17 beta level (GH area/E2: r = 0.98; p less than 0.005) and the serum estrone level (GH area/E1: r = 0.81; p less than 0.05). In men the GH response to TRH/GnRH did not correlate with estrogen or androgen levels. We conclude that high physiological levels of estrogens are pertinent to the activation of a histamine-induced GH response to TRH/GnRH in women, whereas the role of androgens and estrogens for the induction of the response in men seems more complex.(ABSTRACT TRUNCATED AT 250 WORDS)
Knigge
U
U
Department of Surgical Gastroenterology, Hvidovre Hospital, University of Copenhagen, Denmark.
Thuesen
B
B
Dejgaard
A
A
Svenstrup
B
B
Bennett
P
P
D000328:Adult; D000728:Androgens / Q000097:blood*; D004958:Estradiol / Q000097:blood; D004967:Estrogens / Q000097:blood*; D004970:Estrone / Q000097:blood; D005260:Female; D005498:Follicular Phase; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology*; D013006:Growth Hormone / Q000378:metabolism*; D006632:Histamine / Q000494:pharmacology*; D006801:Humans; D008183:Luteal Phase; D008297:Male; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology*
D000728:Androgens; D004967:Estrogens; D004970:Estrone; D007987:Gonadotropin-Releasing Hormone; D004958:Estradiol; D013973:Thyrotropin-Releasing Hormone; D006632:Histamine; D013006:Growth Hormone