Primary structure and pharmacological activity of a nonapeptide related to neuromedin U isolated from chicken intestine.
An extract of chicken intestine contained neuromedin U-like immunoreactivity (36 pmol/g wet tissue weight). The primary structure of the predominant molecular form (NMU-9), comprising 94% of the total immunoreactivity, was established as: Gly-Tyr-Phe-Phe-Phe-Arg-Pro-Arg- Asn-NH2. This sequence differs from that of pig neuromedin U-8 (NMU-8) by the substitution of Leu3 by Phe and, like the corresponding peptide from the guinea pig, is extended from the NH2-terminus by a Gly residue. A minor component of neuromedin U comprised 25 amino acid residues. An extract of chicken whole brain contained much less NMU-like immunoreactivity (1.5 pmol/g) and the nonpeptide was the only molecular form detected. Synthetic chicken NMU-9 produced a concentration-dependent contraction of smooth muscle from the rat uterus and its effect was unchanged in the presence of tetrodotoxin, atropine and indomethacin. The potency of chicken NMU-9 (EC50 360 +/- 60 nM; mean +/- S.E., n = 6) was approximately 8-fold less than that of pig NMU-8 (EC50 46 +/- 8 nM) but the maximum contraction produced by both agonists was not significantly different.
O'Harte
F
F
Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, NE 68178.
Bockman
C S
CS
Zeng
W
W
Abel
P W
PW
Harvey
S
S
Conlon
J M
JM
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002645:Chickens; D002851:Chromatography, High Pressure Liquid; D005260:Female; D066298:In Vitro Techniques; D007413:Intestinal Mucosa / Q000378:metabolism*; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000737:chemistry / Q000494:pharmacology*; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains; D014590:Uterine Contraction / Q000187:drug effects
D000596:Amino Acids; D009479:Neuropeptides; C056900:neuromedin U; C073046:neuromedin U 9