1976 Volume 23 Issue 5 Pages 435-438
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.