Biological activities of tyrosine-containing somatostatin analogs on inhibition of secretion of thyrotropin and growth hormone.
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.
D000818:Animals; D013006:Growth Hormone / Q000378:metabolism*; D008297:Male; D051381:Rats; D013004:Somatostatin / Q000031:analogs & derivatives* / Q000494:pharmacology; D013329:Structure-Activity Relationship; D013972:Thyrotropin / Q000378:metabolism*; D014443:Tyrosine
D014443:Tyrosine; D013004:Somatostatin; D013972:Thyrotropin; D013006:Growth Hormone