The neuropeptide TRH has a minor effect on the enzymatic activity of acetylcholinesterase in vitro.
The neuropeptide thyrotropin-releasing hormone (TRH) elicits a variety of physiological effects of which some are due to cholinergic mechanisms. TRH modulates in vivo the effects of compounds affecting acetylcholinesterase (AChE). In the present study the in vitro effects of TRH on the activity of AChE were explored. TRH has no effect at physiologically relevant concentrations. At unphysiologically high concentrations (>5 mM) a slight inhibition was found. This was noticed also when the enzyme was exposed to the amide-free tripeptide analog p-Glu-His-Pro. We conclude that any cholinergic effect of TRH observed in vivo is unlikely to be due to a direct interaction of the peptide with AChE.
Koskinen
L O
LO
Department of Biomedicine, Defense Research Establishment, Umeå, Sweden. Lars-Owe.Koskinen@neuro.umu.se
Koch
M L
ML
Puu
G
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D000110:Acetylcholinesterase / Q000378:metabolism*; D000122:Acetylthiocholine / Q000378:metabolism; D002800:Cholinesterase Inhibitors / Q000494:pharmacology*; D004228:Dithionitrobenzoic Acid / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology / Q000502:physiology*
D002800:Cholinesterase Inhibitors; D000122:Acetylthiocholine; D013973:Thyrotropin-Releasing Hormone; D004228:Dithionitrobenzoic Acid; D000110:Acetylcholinesterase