Inhibitory effect of somatostatin on abnormal GH response to TRH in primary hypothyroidism.
Thyrotropin releasing hormone (TRH) does not promote GH secretion in normal subjects but it stimulates GH in a proportion of hypothyroid patients. In this study the response of GH to thyrotropin releasing hormone (TRH) was evaluated in 21 patients with primary hypothyroidism of different origin: 12 with autoimmune thyroiditis, 3 idiopathic, 3 congenital, 3 iatrogenic. 11 of these patients had never been treated, the others were tested after a drug-free period of at least two weeks. Basal plasma concentration of GH was normal in all patients; after TRH administration, a significant increase in plasma GH was observed in 4 patients. In these responsive patients, somatostatin infusion inhibited the abnormal GH response to TRH. It is suggested that the abnormal GH response to TRH in primary hypothyroidism might be caused by a relative deficiency of somatostatinergic control, which is corrected by exogenous somatostatin administration.
Cattedra di Semeiotica Medica I, Università di Milano, Italy.
M
M
Baldini
A
A
Catania
A
A
Orsatti
M G
MG
Manfredi
P
P
Motta
L
L
Cantalamessa
D000328:Adult; D000368:Aged; D005260:Female; D013006:Growth Hormone / Q000097:blood*; D006801:Humans; D007037:Hypothyroidism / Q000097:blood*; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D011863:Radioimmunoassay; D013004:Somatostatin / Q000008:administration & dosage / Q000494:pharmacology*; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology*
D013004:Somatostatin; D013973:Thyrotropin-Releasing Hormone; D013006:Growth Hormone