The ability of RX 77368 - a stabilised analogue of TRH - to provoke the secretion of prolactin and TSH in vivo.
RX 77368, a stabilised analogue of TRH, has been evaluated for its ability to provoke the release of TSH and prolactin in vivo after intravenous administration to rats and human volunteers. The analogue caused a dose-related release of TSH in both species. In rats the compound caused release of prolactin but the dose-response relationship was bi-phasic, so that large doses caused only a diminished response. The prolactin response in human volunteers was equivocal and further experiments will be necessary to define the effect. Despite its greater biological stability the potency, efficacy and duration of effect with RX 77368 was similar to that of TRH in both species. The manner in which further endocrine investigations may aid the clinical development of RX 77368 is discussed.
D000818:Animals; D004305:Dose-Response Relationship, Drug; D006801:Humans; D007700:Kinetics; D008297:Male; D011388:Prolactin / Q000378:metabolism*; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives; D051381:Rats; D011919:Rats, Inbred Strains; D013972:Thyrotropin / Q000378:metabolism*; D013973:Thyrotropin-Releasing Hormone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology
D013973:Thyrotropin-Releasing Hormone; C027979:L-pyroglutamyl-L-histidyl-3,3-dimethylprolinamide; D011388:Prolactin; D013972:Thyrotropin; D011761:Pyrrolidonecarboxylic Acid