Determination of L-carnitine in human seminal plasma by HPLC method and its clinical significance / 中华检验医学杂志

ABSTRACT

Objective To develop and validate a simple and reliable HPLC method for the analysis of L-carnitine in human seminal plasma and to investigate its clinical significance as a potentially useful index of infertile.Methods After proteins in seminal plasma are precipitated with acetonitrile,L-carnitine in seminal plasma was derivatized to form its ester.HPLC separation of the sample solution was performed on a Lichrospher SiO_2 column and detected by ultraviolet absorbance at 260 nm.A mobile phase composed of acetonitrile-citrie acid buffer(containing 12 mmol/L triethanolamine,pH 5.0)was found to be the most suitable for this separation at a flow rate of 1.2 ml/min and enabled the baseline separation of the L-carnitine from interferences with isocratic elution.The L-carnitine levels in seminal plasma were studied in both 87 patients with infertility and 30 control subjects.Results Under the chromatographic conditions described, the L-carnitine derivative had a retention time of approximately 13 min.Good separation and detectability of L-carnitine in human seminal plasma sample were obtained.The method proved to be linear in the range of L-carnitine from 0 ?mol/L to 1000 ?mol/L.The relative standard deviations of within-and between-assay for L-carnitine analysis were 1.23% and 1.36%,respectively.The recoveries were 91.6% -96.5% for the human seminal plasma samples.L-carnitine concentrations in the populations were(392.7?107.2)?mol/L in the fertile group(n=30),(270.0?83.9)?mol/L in asthenozoospermia group(n=29),(187.9? 43.9)?mol/L in oligozoospermia group(n=19)and(175.7?67.1)?mol/L in oligoasthenozoospermia group(n=39).The large difference(P0.05).Conclusion The determination of L-carnitine level in seminal plasma may prove useful as a potentially biochemical marker of fertility and this is a useful guidance for the clinic therapy and the mechanismic study on the male reproduction.