The growth hormone response to thyrotropin-releasing hormone in insulin-dependent diabetics involves a cholinergic mechanism.
In order to establish whether cholinergic receptors mediate GH secretion induced by TRH in insulin-dependent diabetes, 10 patients were treated with pirenzepine, an anticholinergic agent, and tested with TRH. Basal concentrations of GH were elevated in these patients and 8 of 10 patients responded to TRH with a significant rise in GH levels. Pretreatment with pirenzepine (40 mg given iv 10 min before TRH) suppressed the TRH-induced GH rise. Pirenzepine had no effect on TRH-induced TSH release. This finding suggests that a cholinergic mechanism is involved in the paradoxical response of GH to TRH in diabetic patients.
D000328:Adult; D001570:Benzodiazepinones; D003922:Diabetes Mellitus, Type 1 / Q000097:blood* / Q000503:physiopathology; D013006:Growth Hormone / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010275:Parasympathetic Nervous System / Q000187:drug effects / Q000503:physiopathology*; D010890:Pirenzepine; D013972:Thyrotropin / Q000097:blood; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology*
D001570:Benzodiazepinones; D010890:Pirenzepine; D013973:Thyrotropin-Releasing Hormone; D013972:Thyrotropin; D013006:Growth Hormone