Synthesis of peptides by the solid-phase method. 7. Substance P and analogs

Abstract

Substance P and 21 related peptides containing isosteric or isofunctional groups were prepared by the solid-phase method. After purification by gel filtration and ion-exchange chromatography, the compounds were characterized by TLC, paper electrophoresis, and amino acid and elemental analysis. The biological activities of the peptides were evaluated in vitro on the guinea pig ileum, the rabbit mesenteric vein, the dog common carotid artery and in vivo on the rat blood pressure. The replacement of some residues in the undecapeptide substance P causes variable losses of apparent affinity with a little or no change in the intrinsic activity. All the analogs used were inactive as antagonists.