Fig. 4.

Measurement of intracellular ADMA in THP1 cells. a) ADMA product ion scan showing the specific fragment at m/z 203.2 which represents the positive ESI tandem mass spectra of i) ADMA reference standard ii) THP1 cell lysate and iii) THP1 cell lysate spiked with reference standard. b) and c) RP-HPLC quantification of ADMA with photodiode detection. Chromatograms of the pre-treated lysates [(i)–Control, (ii)–Doxorubicin (DOX, 2 μM), (iii)–Forskolin (FSK, 10 μM), (iv)–Metformin (MET, 1 μM), (v)–DOX+MET, (vi)–DOX+FSK, (vii)–FSK+MET, (viii)–DOX+MET+FSK] and ADMA reference standard (ix), 200 μg/ml have been reported for comparison of retention time of the standard with that of cell lysates. Data demonstrate the effect of test compounds on intracellular methylarginine concentrations. Results are the mean ± SD of three measurements. *-significantly different at P < 0.05 as compared with the respective control.