AIM:The present study was to investigate the regulation mechanism of
Polydatin on human blood vessels.METHOD:The changes
of the cytosolic free calcium concentration and cell membrane potential of cultured vascular smooth muscle cells (VSMC) were determined kinetically between passages 3 and 8 isolated from human umbilicus artery.RESULTS:
Polydatin (0.5 mmol/L) caused a persistent increase of intracellular calcium concentration
i,which was inhibited completely by pretreatment with EGTA(2 mmol/L) and verapamil(50 μmol/L)10 min prior to Polydatin givening,and was also blocked completely by pretreatment with EGTA and heparin(765×10 3 U/L).But the effect of polydatin on i was enhanced by pretreatment with EGTA and procaine(10 mmol/L).Polydatin can also make the cell membrane potential less negative or depolarized 10 min after polydatin adding.The effects of Polydatin were enhanced significantly by pretreatment with cimetidine,but it was inhibited completely by pretreatment with tetrodotoxin(2.5μmol/L),a kind of sodium channel blocker CONCLUSIONS:Polydatin-induced alternation ini might be mainly due to the entry of extracellular Ca 2+ into cells and release from IP3 sensitive intracellular calcium store,and ryanodine receptor system might regulate negatively IP3 receptor system. And polydatin might induce the entry of sodium ion into cells and cause the depolarization of VSMC.