Recent advances in the development of nonpeptide somatostatin receptor ligands.

Somatostatin (SRIF) is a cyclic peptide that occurs in two biologically active forms, SRIF-14 and SRIF-28. These peptides inhibit the secretion of many other peptides, including insulin and glucagon, function as neurotransmitters or neuromodulators, and exhibit potent antiproliferative activity. Recent research has led to the development of nonpeptide SRIF ligands with high affinity and selectivity at all SRIF receptor subtypes. Additionally, the newly discovered sst(2)and sst(3) antagonists will greatly facilitate our understanding of these receptors. These novel nonpeptide SRIF agonists and antagonists may have therapeutic potential in a variety of disease states.