Aim To investigate the effects of(S,S)ZX-5 and(R,R)ZX-5 on eNOS mRNA and protein levels.Methods Cell culture was used for the experiments in vitro.The effects of eNOS mRNA were investigated by RT-PCR.The effects of eNOS protein levels were investigated by Western blot.Results(S,S)ZX-5 in concentration of 30 mg?L-1 up-regulated eNOS expressions at protein and mRNA levels significantly in cultured ECV304(P