Effects of hyperhomocysteinemia on function of endothelium and serum concentration of vascular cell adhesion moleculeª²1 (VCAMª²1)

    GE Yuª²Xia, DUAN Yunª²You, RUAN Liª²Tao,CAO Tieª²Sheng, YUAN Li Jun, L¨¹ Faª²Qin, LIU Xi

    Department of Ultrasound Diagnostics, Tangdu Hospital, Fourth Military Medical University, Xi¬ðan 710038, China

    ¡¾Abstract¡¿ AIM: To investigate the effects of hyperhomocysteinemia HHCY on the function of endothelium by observing the changes of NO, ET and the activity of GSHª²PX and vascular cell adhesion moleculeª²1 (VCAMª²1) in plasma of HHCY rabbits. METHODS: Eighteen New Zealand rabbits were randomized into methionine group(group B, n=9)and control group (group A, n=9). Methionine group was fed with methionineª²rich diet of Lª²methioine (0.8 g/kg per day) and normal control group was fed with normal diet. The levels of NO, GSHª²PX in plasma and the serum concentration of VCAMª²1 were measured at 20, 40, 60 and 80 d, and endothelium dependent dilation (EDD) and endothelium independent dilation (EID) were examined by high resolution ultrasound. RESULTS: In chronic hyperhomocysteinemia, the EDD of external iliac artery in methioine group was reduced significantly than that in control: 0 d, (15.3¡À2.6)%, 20 d, (5.1¡À1.7)%; 40 d, (2.7¡À1.0)%, 60 d, (-4.1¡À1.3)% and 80 d, (-5.5¡À1.3)% (P<0.01). The EID in group B was reduced significantly compared with that in group A. The values of plasma in methioine group were markedly higher than those in the control group (P<0.05) while the levels of NO were lower than those in the control. In methioine group, the serum concentration of VCAMª²1 was also significantly higher than that in the control group: 0 d, (0.066¡À0.003) ¦Ìg/L, 20 d, (0.074¡À0.004) ¦Ìg/L, 40 d, (0.078¡À0.008) ¦Ìg/L, 60 d, (0.087¡À0.008) ¦Ìg/L and 80 d, (0.098¡À0.010) ¦Ìg/L (P<0.01). CONCLUSION: Chronic hyperhomocysteinemia leads to endothelia dysfunction in rabbits. EDD is reduced through the inactivation of NO by homocysteinemia and the serum concentration of VCAMª²1 is elevated in hyperhomocysteinemia, which is related to the increased oxidative stress and decreased NO level. ......