Enhanced plasma GH responses to simultaneous administration of TRH and GHRH in patients with primary hypothyroidism.
The mechanism of aberrant GH responses to TRH was indirectly evaluated in 7 patients with primary hypothyroidism. All patients showed GH response to TRH. When TRH was administered together with GHRH, the plasma GH response was much greater than after a single administration of TRH or GHRH (TRH+GHRH vs. TRH or GHRH: max. delta GH, 16.4 +/- 3.2 vs. 5.4 +/- 1.3 or 6.0 +/- 0.8 microgram/L; AUC, 1282.7 +/- 234.7 vs. 384.0 +/- 95.0 or 441.8 +/- 66.2, both P < 0.01). The combined administration of TRH and GHRH caused an additive, but not a synergistic, GH response. In contrast, 8 normal subjects showed neither any plasma GH response to TRH nor enhancement by TRH of GHRH-induced GH response following combined administration. It is concluded that the sites of action of TRH seemed to be different from GHRH in patients with primary hypothyroidism.
Hanew
K
K
Second Department of Internal Medicine, Tohoku University School of Medicine, Sendai, Japan.
Utsumi
A
A
Sugawara
A
A
Tanaka
A
A
Fukazawa
H
H
Yoshida
K
K
Abe
K
K
D000328:Adult; D000368:Aged; D004359:Drug Therapy, Combination; D005260:Female; D013006:Growth Hormone / Q000097:blood* / Q000187:drug effects; D013007:Growth Hormone-Releasing Hormone / Q000494:pharmacology*; D006801:Humans; D007037:Hypothyroidism / Q000097:blood* / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology*
D013973:Thyrotropin-Releasing Hormone; D013006:Growth Hormone; D013007:Growth Hormone-Releasing Hormone