Background: The aim of this study was to determine the concentrations of L-arginine and methylarginines in follicular fluid obtained from women participating in our IVF program and to find clinical correlates of these biochemical parameters.
Methods: Follicular fluid was obtained from 108 women by ultrasonography guided transvaginal puncture following controlled ovarian hyperstimulation. Follicular fluid L-arginine, asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA) and monomethylarginine (MMA) concentrations were determined with liquid chromatography-tandem mass spectrometry. The integrated index of arginine methylation (arg-MI) was calculated according to the formula: arg-MI = (ADMA + SDMA)/MMA.
Results: There were significant inverse relationships between IVF embryo number and follicular fluid L-arginine (r = -0.507, P < 0.001), ADMA (r = -0.356, P < 0.024), SDMA (r = -0.347, P < 0.028), MMA (r = -0.449, P < 0.004) and to L-arginine/ADMA ratio (r = -0.328, P < 0.031). By contrast, arg-MI was directly related to IVF embryo number (r = 0.426, P < 0.006). Moreover, the number of IVF oocytes was also inversely related to ADMA (r = -0.202, P < 0.037) and MMA (r = -0.384, P < 0.012) and positively to arg-MI (r = 0.450, P < 0.03).
Conclusions: The elevated levels of follicular fluid l-arginine and methylarginines appear to have an adverse influence on the reproductive processes as reflected by a reduction in the number of oocytes and embryos conceived. In contrast, the integrated methylation index proved to be positively correlated to the above parameters of fertilization.