title: Primary structures and effects on gastrointestinal motility of tachykinins from the rainbow trout.
abstract: Purification and structural characterization of tachykinins from rainbow trout (Oncorhynchus mykiss) intestine has demonstrated the presence of three different peptides related to the mammalian tachykinins: substance P, neurokinin A, and neuropeptide-gamma. The substance P- and the neurokinin A-related peptides present in the intestine are identical to the tachykinins previously isolated from the trout brain. The neuropeptide-gamma-related peptide (Ser-Ser-Ala-Asn-Pro-Gln-Ile-Thr-Arg-Lys-Arg-His-Lys-Ile-Asn-Ser-Phe- Val-Gly-Leu-Met-NH2), not previously identified in brain tissue, has the sequence of the neurokinin A-related tachykinin at its COOH-terminus. Both trout substance P and neurokinin A stimulated the motility of isolated trout intestinal muscle [pD2(-log of EC50) values 8.5 +/- 0.15 and 7.35 +/- 0.08, respectively] and the vascularly perfused trout stomach (pD2 values 9.63 +/- 0.23 and 8.18 +/- 0.23, respectively). Trout substance P was 14 times more potent than trout neurokinin A in the intestine and 28 times more potent in the stomach. The data suggest that receptors interacting with tachykinins in the trout gastrointestinal tract have a similar selectivity as the mammalian NK-1 receptor.
authors.affiliation: Department of Biomedical Sciences, Creighton University, Omaha, Nebraska 68178.
authors.forename: J
authors.initials: J
authors.lastname: Jensen
authors.forename: K R
authors.initials: KR
authors.lastname: Olson
authors.forename: J M
authors.initials: JM
authors.lastname: Conlon
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D005769:Gastrointestinal Motility / Q000187:drug effects*; D007422:Intestines / Q000737:chemistry / Q000187:drug effects; D008969:Molecular Sequence Data; D015288:Neurokinin A / Q000378:metabolism; D009479:Neuropeptides / Q000302:isolation & purification; D017686:Oncorhynchus mykiss / Q000378:metabolism*; D010446:Peptide Fragments / Q000302:isolation & purification; D011863:Radioimmunoassay; D013373:Substance P / Q000378:metabolism; D015320:Tachykinins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology*; D014020:Tissue Extracts / Q000378:metabolism
chemical_list: D009479:Neuropeptides; D010446:Peptide Fragments; D015320:Tachykinins; D014020:Tissue Extracts; C059905:tachykinin neuropeptide gamma; D013373:Substance P; D015288:Neurokinin A