The plasma TXB2 and PGI2 were measured using commercially
available ELISA kit (Cusabio, USA) according to the
manufacturer’s instruction.13,18 The intensity of coloured
product was measured at absorbance 450 nm in a micro
plate reader (VERSA, USA). The result was calibrated by
the software calculation that was provided with the micro
plate reader and compared to the calibration standard
curve.