Oxaprotiline: enantioselective noradrenaline uptake inhibition indicated by intravenous amine pressor tests but not α 2-adrenoceptor binding to intact platelets in man
Received: 04 February 1992 Accepted: 19 August 1992 DOI:
Cite this article as: Reimann, I.W., Firkusny, L., Antonin, K.H. et al. Eur J Clin Pharmacol (1993) 44: 93. doi:10.1007/BF00315288 Summary
The optically active isomers of the racemic tetracyclic antidepressant oxaprotiline, R (−) oxaprotiline CGP 12 103 A (levoprotiline) and the S (+) oxaprotiline CGP 12 104 A, have been used as tools for a methodological Phase I study.
Only the S (+) enantiomer CGP 12 104 A inhibits noradrenaline uptake.
Intravenous amine pressor tests and ex vivo measurement of α
2-adrenoceptor binding to intact human platelets were compared with respect to their reliability in indicating CGP 12 104 A-induced amine uptake inhibition and possibly associated α 2-receptor down-regulation in healthy subjects.
2-Adrenoceptor binding on intact human platelets did not distinguish between CGP 12 104 A and CGP 12 103 A.
However, amine pressor tests reflected the amine uptake inhibiting effect of CGP 12 104 A as a 5-fold decrease in tyramine pressor sensivity and a 5-fold increase in noradrenaline pressor sensitivity.
Key words Oxaprotiline Levoprotiline noradrenaline uptake inhibitors enantiomers CGP 12 103 A CGP 12 104 A amine pressor tests α 2-adrenoceptor binding intact human platelets References
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