Species and tissue specificity of vasoactive regulatory peptides

Peptide regulatory systems are increasingly being implicated in inflammatory processes through their actions on vascular function. Peptides released by sensory nerves (substance P and calcitonin gene-related peptide) and autonomic nerves (neuropeptide Y), or generated by endothelium (angiotensin II) or injured tissues (bradykinin), regulate vascular tone, permeability and proliferation. Peptide systems comprise multiple components responsible for generation, release and metabolism of peptides, as well as receptor expression, combinations of which act together to produce a particular biological effect. Each of these components may vary between species, between tissues and during disease, and the particular combination of these components contributes to the specificity of peptide regulation of tissue function. Understanding the species and tissue specificity of peptide-induced responses is important in developing animal models of human disease and in developing drugs for subsequent use in man. In this paper we review some of the evidence for and implications of species and tissue specificity of vasoactive peptide systems.