Enantioselective high-performance liquid chromatographic analysis of the 5-HT1A receptor agonist 8-hydroxy-2-(di-n-propylamino)tetralin. Application to a pharmacokinetic-pharmacodynamic study in rats.
A rapid, sensitive and enantioselective HPLC assay for the simultaneous determination of the reference 5-HT1A receptor agonists, R-(+)- and S-(-)-8-hydroxy-2-(di-n-propylamino)tetralin (R-8-OH-DPAT and S-8-OH-DPAT, respectively), in rat blood is presented. A selective extraction procedure was developed using a preliminary sample clean-up followed by isolation of R- or S-8-OH-DPAT on mixed-mode NARC-2 solid-phase columns. Separation of the enantiomers was performed by high-performance liquid chromatography using a Chiracel OD-R column. Detection was obtained using an electrochemical detector set at a voltage of 0.63 V. The mobile phase consisted of a 50 mM phosphate buffer (pH 5.5)-acetonitrile (80:20, v/v) mixture. At a flow-rate of 1 ml min(-1), the total run time was approximately 14 min. The limit of detection for R- and S-8-OH-DPAT was 0.5 ng ml(-1). In the concentration range between 50 ng ml(-1) and 1000 ng ml(-1) intra- and inter-day relative standard deviations were less than 12%. The assay was applied to a pharmacokinetic-pharmacodynamic study in rats in which decrease of body temperature was used as a measure of 5-HT1A receptor-mediated effect. Values for clearance, volume of distribution at steady state and terminal elimination rate constant were 22+/-2 ml min(-1), 1969+/-473 ml and 156+/-34 min for R-8-OH-DPAT and 16+/-1 ml min(-1), 3353+/-347 ml and 334+/-36 min for S-8-OH-DPAT, respectively. No enantiomeric interconversion was observed in vivo from R-8-OH-DPAT to S-8-OH-DPAT or vice versa.
Zuideveld
K P
KP
Leiden/Amsterdam Center for Drug Research, Division of Pharmacology, Sylvius Laboratory, Leiden, The Netherlands. zuidevel@lacdr.leidenuniv.nl
Treijtel
N
N
Van der Graaf
P H
PH
Danhof
M
M
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000097:blood / Q000493:pharmacokinetics* / Q000494:pharmacology*; D000818:Animals; D001831:Body Temperature / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D007700:Kinetics; D016014:Linear Models; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D011985:Receptors, Serotonin / Q000378:metabolism*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017366:Serotonin Receptor Agonists / Q000097:blood / Q000493:pharmacokinetics* / Q000494:pharmacology*; D013237:Stereoisomerism
D011985:Receptors, Serotonin; D017366:Serotonin Receptor Agonists; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin