Objective: To compare the protective effect of Tea polyphenol with that of esmolol on vascular endothelial cells secreting endothelin induced by hypoxia combined Ang-2. Methods: Vascular endothelial cells were divided into 4 groups that included control group

hypoxia+Ang-2 group

hypoxia+Ang-2+tea polyphenol group

hypoxia+Ang-2+esmolol group

and each group comprised eight samples. The changes of endothelin expression level were measured with radioimmunoassay at the time of 0.5 h

6 h

and 24 h. Results: ①The level of endothelin expression in hypoxia+Ang-2 group was higher significantly than that in the control group(P<0.01);②The level of endothelin expression in the hypoxia+Ang-2+tea polyphenol group was lower significantly than that in hypoxia+Ang-2 group(P<0.01);③The level of endothelin expression in the hypoxia+Ang-2+esmolol group was lower significantly than that in hypoxia+Ang-2 group(P<0.01);④There was not different in level of endothelin expression between the hypoxia+Ang-2+tea polyphenol group and the hypoxia+Ang-2+ esmolol group at the time of 0.5 h after hypoxia combined Ang-2(P>0.05)

but there was significantly different at the time of 6 h and 24 h after hypoxia combined Ang-2(P<0.01).Conclusion:Both hypoxia combined Ang-2 can induce obvious change of endothelin expression level in endothelial cell and this change can be reduced significantly by tea polyphenol and esmolol

the protective effect of tea polyphenol is more obvious compared with that of esmolol.