Biological Activities of Tyrosine-Containing Somatostatin Analogs on Inhibition of Secretion of Thyrotropin and Growth Hormone

抄録

The following five tyrosine-containing analogs of somatostatin (GIF) were synthesized by the solid-phase method: Tyr-GIF;[Tyr⁶]-GIF;[Tyr⁷]-GIF;[Tyr⁸]-GIF;[Tyr¹¹]-GIF.These analogs except [Tyr⁸]-GIF were demonstrated to possess almost the same potency to inhibit thyrotropin release stimulated by thyrotropin-releasing hormone as that of synthesized GIF in vivo.[Tyr⁸]-GIF had potencies less than 0.5% of GIF. They also had the activity to inhibit Nembutal-induced growth hormone rise. The structure-activity relationship and availability of these analogs for radioimmunoassay were discussed.