title: A cyclic analogue selective for the NKB specific binding site on rat brain synaptosomes.
abstract: The cyclic analogue of NKB, [Cys2,Cys5]NKB is as active as SP and NKB in the guinea-pig ileum bioassay. Furthermore, [Cys2,Cys5]NKB is a selective substrate for the [3H]NKB specific binding site on rat cortical synaptosomes. Its binding potencies for [3H]NKB and 125I-BHSP binding sites, IC50 = 5.2 nM and 3.4 microM respectively were close to those observed for NKB.
mesh_terms: D000818:Animals; D001923:Brain Chemistry / Q000187:drug effects*; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007457:Iodine Radioisotopes; D009130:Muscle, Smooth / Q000187:drug effects; D015287:Neurokinin B / Q000031:analogs & derivatives*; D010456:Peptides, Cyclic / Q000138:chemical synthesis / Q000494:pharmacology*; D013373:Substance P / Q000494:pharmacology; D013574:Synaptosomes / Q000378:metabolism*
chemical_list: D007457:Iodine Radioisotopes; D010456:Peptides, Cyclic; C050721:neuromedin K, cyclic Cys(2,5)-; D013373:Substance P; D015287:Neurokinin B