Polyamines and the NMDA receptor: modifying intrinsic activities with aromatic substituents.
Thirty-four spermidine (SPD) and spermine (SPM) derivatives with aromatic substituents were synthesized and tested as inhibitors of specific binding of the NMDA channel blocker [3H]MK-801 to membranes prepared from rat hippocampus and cerebral cortex. SPD and SPM derivatives with aromatic substituents at the primary amino groups were the most potent inhibitors (IC50 3.9-4.7 microM). These compounds most likely act directly at the NMDA ion channel, since 30 microM SPM had no pronounced influence on their inhibiting activities. SPD derivatives with aromatic substituents at the secondary amino group were either inactive or highly SPM-sensitive inhibitors (IC50 10-82 microM), depending on the size of the substituent. Our results support the hypothesis that an aromatic interaction site near the center of polyamine derivatives contributes to polyamine inverse agonism.
Berger
Michael L
ML
Molecular Neurobiology, Center for Brain Research, Medical University Vienna, Austria. michael.berger@meduniwien.ac.at
Bitar
Abdallah Y
AY
Waitner
Matthew J
MJ
Rebernik
Patrick
P
O'Sullivan
Mary C
MC
D000818:Animals; D015394:Molecular Structure; D011073:Polyamines / Q000737:chemistry* / Q000378:metabolism*; D051381:Rats; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D013329:Structure-Activity Relationship
D011073:Polyamines; D016194:Receptors, N-Methyl-D-Aspartate