title: Novel secoergoline derivatives inhibit both GABA and glutamate uptake in rat brain homogenates: synthesis, in vitro pharmacology, and modeling.
abstract: Three of twelve secoergoline derivatives (Z ethyl 4-[(ethoxycarbonylmethyl)methylamino]-2-methyl-3-phenylpent-2-enoate, 8; ethyl 1,6-dimethyl-3-oxo-5-phenyl-1,2,3,6-tetrahydropyridine-2-carboxylate, 9; Z methyl 4-[(methoxycarbonylmethyl)methylamino)-2-methyl-3-phenylpent-2-enoate, 11), containing bioisosteric sequences of GABA and Glu, inhibited both GABA and Glu transport through cerebrocortical membranes specifically. Compounds 8, 9, and 11 appeared to be equipotent inhibitors of GABA and Glu transport with IC50 values between 270 and 1100 microM, whereas derivatives 1-7, 10, and 12 were without effects. In the presence of GABA and Glu transport-specific nontransportable inhibitors, inhibition of GABA and Glu transport by 8, 9, and 11 proceeded in two phases. The two phases of inhibition were characterized by IC50 values between 4 and 180 nM and 360-1020 microM and different selectivity sequences. These findings may indicate the existence of some mechanism possibly mediated by a previously unrecognized GABA-Glu transporter. Derivatives with the cis, but not the trans configuration of bulky ester groups (8 vs 7 and 11 vs 12) showed significant inhibitory effect (IC50 values of 270 microM vs >>1000 microM and 1100 microM vs >>1000 microM on GABA transport, respectively). The cis-trans selectivity can be explained by docking these secoergolines in a three-dimensional model of the second and third transmembrane helices of GABA transporter type 1.
authors.affiliation: Department of Neurochemistry, Chemical Research Center, Hungarian Academy of Sciences, H-1025 Pusztaszeri út 59-67, Organic Chemistry Institute, Budapest University of Technology and Economics, H-1111 Gellért tér 4, Budapest, Hungary.
authors.forename: László
authors.initials: L
authors.lastname: Héja
authors.forename: Ilona
authors.initials: I
authors.lastname: Kovács
authors.forename: Eva
authors.initials: E
authors.lastname: Szárics
authors.forename: Mária
authors.initials: M
authors.lastname: Incze
authors.forename: Eszter
authors.initials: E
authors.lastname: Temesváriné-Major
authors.forename: Gábor
authors.initials: G
authors.lastname: Dörnyei
authors.forename: Mária
authors.initials: M
authors.lastname: Peredy-Kajtár
authors.forename: Eszter
authors.initials: E
authors.lastname: Gács-Baitz
authors.forename: Csaba
authors.initials: C
authors.lastname: Szántay
authors.forename: Julianna
authors.initials: J
authors.lastname: Kardos
mesh_terms: D000596:Amino Acids / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D004873:Ergolines / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D018756:GABA Antagonists / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D018698:Glutamic Acid / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D008958:Models, Molecular; D011869:Radioligand Assay; D051381:Rats; D017208:Rats, Wistar; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
chemical_list: D000596:Amino Acids; D004873:Ergolines; D018691:Excitatory Amino Acid Antagonists; D018756:GABA Antagonists; C494339:ethyl 4-((ethoxycarbonylmethyl)methylamino)-2-methyl-3-phenylpent-2-enoate; D018698:Glutamic Acid; D005680:gamma-Aminobutyric Acid