Isocyanines and pseudoisocyanines as a novel class of potent noradrenaline transport inhibitors: synthesis, detection, and biological activity.
Noradrenaline, the neurotransmitter of the sympathetic nervous system, is removed from the extracellular space by both neuronal and extraneuronal transport mechanisms. In the past, further investigation of the extraneuronal type of noradrenaline transporter was severely hampered by the lack of potent inhibitors. Here, we describe the synthesis of various novel noradrenaline transport inhibitors which belong to the chemical class of isocyanine and pseudoisocyanine dyes. The biological activity of these compounds was investigated in a tissue culture system (Caki-1 cells). 1,1'-Diisopropyl-2,4'-cyanine, 1,1'-diethyl-2,2'-cyanine, and 1-ethyl-1'-isopropyl-2,2'-cyanine turned out as the most potent inhibitors of the extraneuronal noradrenaline transport known so far. At 100 nmol/L, these compounds diminished extraneuronal noradrenaline transport by about 95%. Their IC50's were below 20 nmol/L. In addition, a rapid and sensitive method (based on HPLC with fluorometric detection) to measure these compounds in body fluids is reported.
Russ
H
H
Department of Pharmacology, University of Würzburg, Germany.
Engel
W
W
Schömig
E
E
D000818:Animals; D002352:Carrier Proteins / Q000037:antagonists & inhibitors*; D002460:Cell Line; D002851:Chromatography, High Pressure Liquid; D004396:Coloring Agents; D003345:Corticosterone / Q000494:pharmacology; D015394:Molecular Structure; D009638:Norepinephrine / Q000378:metabolism; D050484:Norepinephrine Plasma Membrane Transport Proteins; D016716:PC12 Cells; D011804:Quinolines / Q000032:analysis / Q000138:chemical synthesis* / Q000494:pharmacology; D011806:Quinolinium Compounds / Q000032:analysis / Q000138:chemical synthesis* / Q000494:pharmacology; D011817:Rabbits; D027981:Symporters
D002352:Carrier Proteins; D004396:Coloring Agents; D050484:Norepinephrine Plasma Membrane Transport Proteins; D011804:Quinolines; D011806:Quinolinium Compounds; D027981:Symporters; C100254:pseudoisocyanine; D003345:Corticosterone; D009638:Norepinephrine