title: Biological activity of TRH thionalogue and its diastereoisomers.
abstract: Binding affinity and TSH-releasing activity of [Prot3] TRH analogue (L-pyroglutamyl-L-histidyl-L-proline thioamide), TRH and their LDL and LLD diastereoisomers were compared in rats. Binding affinity and dose-related increase of TSH secretion were similar for both [Prot3] TRH and TRH. Moreover, similar effect of both peptides on sleeping time and motoric activity of rat was found. Substitution of L- for D-amino acids of TRH and [Prot3] TRH decreased the binding affinity and TSH-releasing activity as well. It was concluded that [Prot3] TRH analogue is as active as native TRH.
mesh_terms: D000818:Animals; D001667:Binding, Competitive; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D010903:Pituitary Gland, Anterior / Q000187:drug effects / Q000378:metabolism*; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives; D051381:Rats; D011919:Rats, Inbred Strains; D012890:Sleep / Q000187:drug effects; D013237:Stereoisomerism; D013972:Thyrotropin / Q000378:metabolism; D013973:Thyrotropin-Releasing Hormone / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D013973:Thyrotropin-Releasing Hormone; D013972:Thyrotropin; C047483:pyroglutamyl-histidyl-proline thioamide; D011761:Pyrrolidonecarboxylic Acid