Phylogeny of the Tachykinins

Abstract

From a phylogenetic point of view, the progress of tachykinin research has been somewhat uneven. The pioneering studies of Erspamer and co-workers (reviewed in [1])were carried out primarily in amphibia and numerous peptides were isolated from the skin of frogs. Eledoisin, however, was purified from the salivary gland of the Mediterranean octopus, Eledone, a highly developed mollusc. Interest in the diversity of the tachykinin family has increased enormously in recent years with the realization that mammalian nervous tissue contains, in addition to substance P, peptides homologous to the amphibian peptide kassinin i.e. neurokinin A, neurokinin Band neuropeptide K (reviewed in [2]). Previous work in the laboratory has led to the development of region-specific radioimmunoassays for substance P [3,4] and neurokinin A [5]. In this study, these assays are used together with HPLC separation to partially characterize the tachykinin-like peptides in tissues from some representative lower vertebrates: Rainbow trout (teleost), dogfish (elasmobranch), Atlantic hagfish (cyclostome) and sea squirt (protochordate).