ABSTRACT
This chapter provides a brief overview of the structural features of certain recognized biologically active peptides common to both gastroenteropancreatic tissues and to neural structures of the peripheral and central nervous systems. It outlines the primary structures of certain regulatory peptides and the differences in amino acid sequences which occur between mammalian and certain non-mammalian species. The chapter also outlines the structural similarities between certain regulatory peptides which result in their being classified as members of peptide families and important data on structure-function relationships. It describes the primary structures of these peptides, and reference is made to the original literature where possible. The development of long-acting somatostatin agonists has led to an important practical application in the treatment of inoperable malignant neuroendocrine tumors. The development of specific competitive antagonists to the actions of locally acting peptides, such as neuropeptides, will greatly enhance the elucidation of their physiological roles.
