Pasma growth hormone responses to thyrotropin-releasing hormone in the urethane-anesthetized rat.
Intravenous injection of synthetic thyrotropin-releasing hormone (TRH) resulted in a significant and dose-related increase in plasma growth hormone (GH) in the urethane anesthetized rat. The minimum effective does of TRH was 40 ng per 100 g body wt when administered intravenously. The maximum responses of plasma GH to TRH were observed at 5 min following TRH, whereas those of plasma TSH were obtained at 10 min. Pretreatment with either T3 (50 mug/100 g body wt ip) significantly suppressed both plasma GH and TSH responses to TRH. The GH release induced by TRH was significantly inhibited by somatostatin (5 mug/100 g body wt iv) which was injected 5 min and immediately before the injection of TRH.
D000768:Anesthesia, General; D000818:Animals; D003864:Depression, Chemical; D004305:Dose-Response Relationship, Drug; D013006:Growth Hormone / Q000097:blood*; D007275:Injections, Intravenous; D008297:Male; D051381:Rats; D013004:Somatostatin / Q000494:pharmacology; D013268:Stimulation, Chemical; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology*; D013974:Thyroxine / Q000494:pharmacology; D013997:Time Factors; D014284:Triiodothyronine / Q000494:pharmacology; D014520:Urethane
D014284:Triiodothyronine; D014520:Urethane; D013004:Somatostatin; D013973:Thyrotropin-Releasing Hormone; D013006:Growth Hormone; D013974:Thyroxine