Tyr-(D-Dab⁴,Arg⁵,D-Trp⁸)-cyclo-Somatostatin-14 (4-11)

High affinity ligand for all five somatostatin receptors (sst1-sst5). In AtT-20 mouse anterior pituitary tumor cells which mainly express sst2 and sst5 receptors the binding affinity of this somatostatin analog was found to be higher than that of somatostatin-14 (H-1490) and octreotide (H-5972). In a model of epileptogenesis, however, KE 108 did not exhibit antiepileptic activity suggesting that the high potency and efficacy of a synthetic ligand to all known somatostatin receptors may not reproduce entirely the effects of the natural ligand.