Determination of the adenosine A(1) agonist N(6)-cyclopentyladenosine in rat blood by solid-phase extraction and HPLC.
A solid-phase extraction procedure has been developed for the isolation of the adenosine A1 receptor agonist N(6)-cyclopentyladenosine from rat blood. The biological samples were spiked with N(6)-cyclopentyladenosine and the analogue N(6)-cyclohexladenosine (internal standard), diluted with sodium hydroxide, loaded onto disposable cartridges with subsequent desorption with methanol and analysis by HPLC. The performance of columns pre-packed with different C18-bonded silica phases or with a polymeric reversed-phase sorbent (Oasis HLB) was assessed. The highest extraction efficiencies (recovery rates>83.3%) for the two N6-alkyl substituted adenosines were achieved by the Oasis HLB cartridges. In addition, the polymeric sorbent provided reproducible recoveries (relative standard deviation<4.8%), whereas large variations (relative standard deviation values, 9--16.3%) in the extraction yields were observed using the conventional silica-based C18 cartridges. The described sample preparation method is rapid, simple, selective and it is suitable for pharmacokinetic studies.
Department of Pharmaceutical Sciences, University of Ferrara, via Fossato di Mortara 17, 44100 Ferrara, Italy. sls@unife.it
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Scalia
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Simeoni
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Dalpiaz
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Villani
D000241:Adenosine / Q000031:analogs & derivatives / Q000097:blood* / Q000493:pharmacokinetics; D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D058906:Purinergic P1 Receptor Agonists; D051381:Rats; D015203:Reproducibility of Results
D058906:Purinergic P1 Receptor Agonists; C048599:N(6)-cyclopentyladenosine; D000241:Adenosine