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Measurement and pharmacokinetic analysis of imipramine and its metabolite by brain microdialysis
Author(s) -
Sato Yuji,
Shibanoki Shinji,
Sugahara Megumi,
Ishikawa Koichi
Publication year - 1994
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1994.tb13120.x
Subject(s) - microdialysis , metabolite , imipramine , pharmacokinetics , pharmacology , medicine , chemistry , central nervous system , pathology , alternative medicine
1 The feasibility of the brain microdialysis method for direct measurement and pharmacokinetic study of imipramine (Imip) and its metabolite desipramine (DMI) was investigated in the rat brain. 2 A dialysis tube was inserted into the right striatum of male Wistar rats, which were administered i.p. with 12.5 mg kg −1 Imip. Thirty μl dialysate was collected every 15 min, and the levels of Imip and DMI were measured by high‐performance liquid chromatography with electrochemical detection (h.p.l.c.–e.c.d.). SKF‐525A and aminopyrine were concomitantly administered in order to assess their respective effects on the pharmacokinetics of Imip and DMI in the brain. 3 The intracerebral half life ( t 1/2 ) of Imip was 2.4 ± 0.3 h with Imip alone. Premedication with SKF‐525A, an inhibitor of drug‐metabolizing enzymes, significantly prolonged the t 1/2 of Imip, while at the same time production of DMI from Imip was accordingly inhibited. Concomitant administration of aminopyrine did not induce any significant change in the concentrations of Imip, but significantly inhibited the concentrations of DMI through its competitive antagonism in the demethylation pathway. 4 The present results suggest that the brain microdialysis method reflects the intracerebral pharmacokinetics of Imip and DMI well and may be applicable to further pharmacokinetic investigations of psychotropic agents.