Somatostatin receptor ligand (Ki values are 142, > 1000, 10.8, 16.6 and 5.7 nM for human cloned sst1 - 5 receptors respectively). Behaves as an antagonist on SRIF14-induced [35S]-GTPγS binding at sst3 and sst5 receptors (PKB values are 6.33 and 5.84 respectively). MW (observed): 1232.49.