Experimental Study On The Effect Of Substance P (SP) On The Secretive Function Of Lipopolysaccharides (LPS)-Injured Endothelial Cells

Objective: To investigate the protective effect of substance P on thesecret1ive function of normal and lipopolysaccharide-injured Human Umbilical VeinEndothelial Cells (HUVEC).Methods: Using a cell line of HUVEC(ECV304), we measured theconcentrations of ET-1 and NO in the supernatant treated with differentconcentrations of SP or SP plus LPS. In addition, the expression of iNOS and eNOSwas analyzed by immunohistochemistry.Results: Different concentrations of SP exerted an obvious effect onstimulating eNOS expression and thus increasing NO production in HUVECs withoutaffecting the expression of iNOS and ET-1. LPS(1mg/L) was able to stimulate thesecretion of NO and ET-1, up-regulate eNOS expression within 30 minutes, whilesuppressed eNOS expression and induced iNOS expression 60 minutes after treatment.Furthermore, addition of SP could obviously attenuate the promoting effect of LPS onNO and ET-1 secretion in HUVECs, and ameliorate the long-term effect ofsuppressing eNOS expression while decreasing iNOS in HUVECs induced by LPS.Conclusion: SP stimulates eNOS expression and thus increases NO productionin HUVECs without affecting iNOS and ET-1 expression. LPS (1mg/L) can stimulateNO and ET secretion, eNOS expression in HUVEC within early 30 minutes. At 1hour after LPS treatment, eNOS expression as well as NO production is significantlyincreased. SP is supposed to has a protective effect on the LPS-injured HUVECs.