Differential effect of fluorinated analogs of TRH on the cardiovascular system and prolactin release.
The effects of thyrotropin-releasing hormone (TRH) and the TRH-analogs, 4-fluoro-Im-TRH (4-F-TRH) and 2-trifluoromethyl-Im-TRH (2-TFM-TRH), on the cardiovascular system and prolactin (PRL) release were examined in conscious rats. TRH (2.8 or 28 nmol) injected into the anterior hypothalamus produced dose-dependent increments in blood pressure and heart rate; plasma PRL was increased twofold after the higher dose of TRH. 4-F-TRH had effects similar to those of TRH on both the cardiovascular and PRL response. In contrast, the 2-TFM-TRH was significantly less active than TRH or 4-F-TRH in eliciting tachycardia, yet was noticeably more potent in affecting PRL release. These data suggest that the receptors for TRH-induced PRL release may be different from TRH-receptors which mediate central cardiovascular responses.
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects*; D007032:Hypothalamus, Anterior / Q000187:drug effects; D008297:Male; D011388:Prolactin / Q000097:blood*; D051381:Rats; D011919:Rats, Inbred Strains; D013973:Thyrotropin-Releasing Hormone / Q000031:analogs & derivatives* / Q000494:pharmacology
C042284:thyrotropin-releasing hormone, 4-fluoroimidazole-; D013973:Thyrotropin-Releasing Hormone; D011388:Prolactin; C042283:thyrotropin-releasing hormone, 2-fluoromethylimidazole-