Neuropeptide gamma, the most potent contractile tachykinin in human isolated bronchus, acts via a 'non-classical' NK2 receptor.
Cumulative contractile response curves to neurokinin A (NKA) and neuropeptide gamma (NP gamma) were obtained in human isolated bronchus, in the presence of phosphoramidon 10 microM. NP gamma was approximately 10-fold more potent than NKA (pD2 values 8.6 +/- 0.4 and 7.3 +/- 0.3 respectively, n = 6; P less than 0.01). The NK1-selective agonist [Sar9, Met(O2)11]-SP and the NK3 selective agonist senktide produced negligible contraction. Response curves to NP gamma and NKA were unaffected by the NK2 subtype-selective antagonist MDL 29913 at 2 microM, but NP gamma-induced contraction was markedly inhibited by 20 microM MDL 29,913. Thus NP gamma is the most potent tachykinin in human isolated bronchus and its effects are mediated at a receptor which is not of the 'classical' NK2 subtype found in hamster urinary bladder.
Burcher
E
E
Department of Pharmacology, University of Sydney, NSW, Australia.
Alouan
L A
LA
Johnson
P R
PR
Black
J L
JL
D000595:Amino Acid Sequence; D001980:Bronchi / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D008969:Molecular Sequence Data; D009119:Muscle Contraction / Q000187:drug effects*; D015288:Neurokinin A / Q000494:pharmacology; D010446:Peptide Fragments / Q000494:pharmacology*; D010456:Peptides, Cyclic / Q000494:pharmacology; D017981:Receptors, Neurotransmitter / Q000187:drug effects; D018039:Receptors, Tachykinin; D015320:Tachykinins / Q000494:pharmacology*
D010446:Peptide Fragments; D010456:Peptides, Cyclic; D017981:Receptors, Neurotransmitter; D018039:Receptors, Tachykinin; D015320:Tachykinins; C059905:tachykinin neuropeptide gamma; C073382:MDL 29913; D015288:Neurokinin A