PT  - JOURNAL ARTICLE
AU  - TOMAS DE PAULIS
AU  - DIANA KELDER
AU  - SVANTE B. ROSS
AU  - NILS E. STJERNSTRÖM
TI  - On the Topology of the Norepinephrine Transport Carrier in Rat Hypothalamus
DP  - 1978 Jul 01
TA  - Molecular Pharmacology
PG  - 596--606
VI  - 14
IP  - 4
4099  - http://molpharm.aspetjournals.org/content/14/4/596.short
4100  - http://molpharm.aspetjournals.org/content/14/4/596.full
SO  - Mol Pharmacol1978 Jul 01; 14
AB  - The conformations of 31 rigid and semirigid compounds structurally related to the tricyclic antidepressant agents have been correlated with their inhibitory activities toward the uptake of norepinephrine in synaptosomes of rat hypothalamus. A relationship was found, in terms of four intramolecular distances, between the potencies of these compounds and their structural similarities to the most potent compound, N,N-dimethylspiro[5H-dibenzo[a,d]cycloheptene-5,1'-cyclohexane]-4-amine (A 1866). The stereochemical parameters were selected to describe the position of the nitrogen atom in relation to the centers of the two aromatic nuclei. It is suggested that the competitive antagonistic behavior of the tricycic compounds is independent of their structural similarities to either the gauche or the anti conformation of norepinephrine. It is concluded that the norepinephrine transport carrier is equipped with active sites displaying two different topologies. One is complementary to the structure of A 1866, for which the tricyclic antidepressant agents have affinity; the other has a topology complementary to the structure of norepinephrine, to which the catecholamines and some phenylalkylamine derivatives fit. ACKNOWLEDGMENT We thank Dr. Brian Pring for linguistic revision of the manuscript.