OBJECTIVETo observe effect of porcine relaxin(pRLX) on NO production of human microvascular endothelial cells(HMVECs) and discuss its possible mechanism.

METHODSiNOS and cNOS expression of HMVECs with or without pRLX were detected using western blotting. NO production of HMVECs with pRLX at different concentration or different time were determined by method of Griess. NO production of pRLX of HMVECs plus Non-selective NOS inhibitor NG-monomethyl-L-arginine(L-NMMA), selective iNOS inhibitor aminoguanidine(AG) or nuclear factors-kappaB (NF-kappaB) inhibitor pyrrolidine dithiocarbamate(PDTC) were also analysed.

RESULTSpRLX promoted iNOS protein expression of HMVECs, but not cNOS protein expression. NO production of HMVECs was promoted by pRLX on concentration-dependent pattern instead of time-dependent one. AG, L-NMMA and PDTC were showed to block the effect of pRLX on NO production of HMVECs.

CONCLUSIONpRLX promote iNOS expression and NO production of HMVECs.