Investigation of the specificity of FK 888 as a tachykinin NK1 receptor antagonist.
1. A recently described peptide tachykinin (NK1) receptor antagonist, FK 888, was found to inhibit the electrically-evoked, tachykinin-mediated contractile responses of the rabbit iris sphincter in a concentration-dependent manner; the pIC50 value was 6.6 +/- 0.08. 2. Contractions induced by a selective NK1 receptor agonist, [Sar9,Met(O2)11]substance P, were inhibited competitively by FK 888; the pKB value was 7. 1. 3. FK 888 (1 nM-100 microM) was without effect on the electrically-evoked, cholinergic response of the rabbit iris sphincter and the electrically-evoked, sympathetic response of the guinea-pig vas deferens. The contractions of the rabbit iris sphincter, induced by either carbachol (10 nM-30 microM) or noradrenaline (0.1-100 microM), were not affected by 10 microM FK 888. 4. FK 888 (1-30 microM) did not induce histamine release from rat peritoneal mast cells. 5. FK 888 (33 and 333 microM) was without effect on the electrically-evoked action potentials of the frog sciatic nerve. Thus, FK 888 is a moderately high affinity and selective tachykinin (NK1) receptor antagonist.[1]References
- Investigation of the specificity of FK 888 as a tachykinin NK1 receptor antagonist. Wang, Z.Y., Tung, S.R., Strichartz, G.R., Håkanson, R. Br. J. Pharmacol. (1994) [Pubmed]
Annotations and hyperlinks in this abstract are from individual authors of WikiGenes or automatically generated by the WikiGenes Data Mining Engine. The abstract is from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.About WikiGenesOpen Access LicencePrivacy PolicyTerms of Useapsburg
