title: [Comparative studies on the affinities of K-II and U-50488H for kappa opiate receptor].
abstract: 3,4-Dichloro-N-methyl-N-[trans-2-(1-delta 3-pyrrolinyl)-cyclohexyl] benzenacetamide hydrochloride (K-II) is a novel analogue of U-50488H. Previous studies have demonstrated that K-II is more potent than U-50488H in analgesic activity in mice and in inhibitory effect on electrically induced contractions of the isolated rabbit vas deferens. In this paper, we determined the affinities of K-II and U-50488H for kappa opiate receptor in guinea pig cerebellum and frontal cortex using radioreceptor binding assay (saturation studies and competition studies), and calculated Ki values of K-II and U-50488H by the Cheng-Prusoff equation. The results indicate that the affinity of K-II for kappa opiate receptor is 6-42 times greater than that of U-50488H. The selectivity of K-II for opiate receptor subtypes is being studied.
authors.affiliation: Bejing Institute of Pharmaceutical Chemistry.
authors.forename: J G
authors.initials: JG
authors.lastname: Li
authors.forename: S C
authors.initials: SC
authors.lastname: Ma
authors.forename: S N
authors.initials: SN
authors.lastname: Lu
authors.forename: C Q
authors.initials: CQ
authors.lastname: Wang
mesh_terms: D019900:3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer; D000700:Analgesics; D000818:Animals; D044482:Benzeneacetamides; D001667:Binding, Competitive; D002531:Cerebellum / Q000378:metabolism; D002540:Cerebral Cortex / Q000378:metabolism; D005260:Female; D006168:Guinea Pigs; D008297:Male; D011758:Pyrroles / Q000378:metabolism*; D011759:Pyrrolidines / Q000378:metabolism*; D011869:Radioligand Assay; D011957:Receptors, Opioid / Q000378:metabolism*; D017473:Receptors, Opioid, kappa
chemical_list: D000700:Analgesics; D044482:Benzeneacetamides; D011758:Pyrroles; D011759:Pyrrolidines; D011957:Receptors, Opioid; D017473:Receptors, Opioid, kappa; C052660:3,4-dichloro-N-methyl-N-(2-(1-delta(3)-pyrrolinyl)-cyclohexyl)benzeneacetamide; D019900:3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer