| Objective:To investigate the mechanism of vascular endothelial dysfunction in rats with Hhcy and and on this basis to evaluate the interventional effects after giving the folic acid, vitamin B12 and Probucol on the measurement of ADMA, Hcy, e NOS, NO levels in rats. Methods:Seventy SD rats were randomly divided into seven groups, including the Control group、Hhcy group、high-dose- probucol group、middle-dose- probucol group、low-dose- probucol group、folic-acid-vitamin B12 group,folic-acid-vitamin B12 and probucol group.each group had ten rats. plain feedstuff was given to the control group, the homomethionin feedstuff was given to the other groups.The homomethionin feedstuff feed the rats eight weeks and then added six kinds of intervention measures for four weeks,such as water, Probucol(three kinds of dose), folic acid and vitamin B12.The time of experiment lasted 12 weeks.The concentration of the total homoeysteine,e NOS,NO level in blood plasma were measured at the beginning,the eighth week and the twelveth week. ADMA and Hcy were measured by high pressure liquid chromatogra Phy analysis(HPLC), e NOS and NO were measured by enzyme-linked immunoassay(ELISA) method.Results:1. When the rats were feed with the High concentrations(2%) of methionine feedstuff for eight weeks, the Hyperhomocysteinemia could be induced successfully, the level of Hcy in blood plasma was increased from6.16 ±0.98μmol/l to 60.24 ± 11.44μmol/l in the Hyperhomocysteinemia model groups.There was no statistically differences(P > 0.05) in seven groups of rats about Hcy、ADMA、e NOS、NO levels at the beginning of the experiment.2. The Hcy levels in plasma of Hhcy group were significantly higher than that of the same period of normal control group at the eighth week and twelveth week(P < 0.01). At the twelveth week, the Hcy levels of groups added the three differentdoses probucol were all lower than that of the same period of Hhcy group(P < 0.05), but were significantly higher than that of the same period of normal control group(P < 0.01), also are higher than the group with the folic acid and vitamin B12(P < 0.05),and the Hcy levels of the group added folic acid and vitamin B12 were significantly lower than that of the same period Hhcy group(P < 0.01), but still higher than that of the same period of normal control group(P < 0.05), the Hcy levels of the group added the folic acid、vitamin B12 and probucol compared with that of the same time in normal control group was not statistically significant(P > 0.05).3. The ADMA levels in plasma of Hhcy group were significantly higher than that of the same period of normal control group at the eighth week and twelveth week(P < 0.01). At the twelveth week, the ADMA levels of groups added the three different doses probucol and group added folic acid and vitamin B12 were all lower than that of the same period of Hhcy group(P < 0.05), but were significantly higher than that of the same period of normal control group(P < 0.01), and that of these four groups were not statistically significant(P < 0.05), the ADMA levels of the group added the folic acid,vitamin B12 and probucol compared with that of the same time in normal control group was not statistically significant(P > 0.05).4. The e NOS levels in plasma of Hhcy group were significantly lower than that of the same period of normal control group at the eighth week and twelveth week(P < 0.01). At the twelveth week, the e NOS levels of groups added the three different doses probucol were all higher than that of the same period of Hhcy group(P < 0.05), but were significantly lower than that of the same period of normal control group(P < 0.01), also are lower than the group added the folic acid and vitamin B12(P < 0.05),and the Hcy levels of the group added folic acid and vitamin B12 were significantly higher than that of the same period Hhcy group(P < 0.01), but still lower than that of the same period of normal control group(P < 0.05), the e NOS levels of the group with the folic acid,vitamin B12 and probucol compared with that of the same time in normal control group was not statistically significant(P > 0.05).5. The NO levels in plasma of Hhcy group were significantly lower than that of the same period of normal control group at the eighth week and twelveth week(P < 0.01). At the twelveth week, the NO levels of groups added the three different doses probucol were all higher than that of the same period of Hhcy group(P < 0.05), but were significantly lower than that of the same period of normal control group(P < 0.01), also are lower than the group added the folic acid and vitamin B12(P < 0.05),and the Hcy levels of the group added folic acid and vitamin B12 were significantly higher than that of the same period Hhcy group(P < 0.01), but still lower than that of the same period of normal control group(P < 0.05), the NO levels of the group added the folic acid,vitamin B12 and probucol compared with that of the same time in normal control group was not statistically significant(P > 0.05).6. Pearson-correlation analysis showed: Plasma levels of ADMA were positively correlated with Hcy(P < 0.01),and were negatively correlated with levels of e NOS and NO(P <0.01); Plasma levels of Hcy were positively correlated with that of ADMA, e NOS and NO(P<0.01).Conclusion:7. The levels of ADMA and Hcy in plasma were raised significantly in rats with high concentrations of methionine feedstuff, as well as the levels of e NOS and NO in serum was reduced obviously, which demonstrated that vascular endothelial dysfunction was prevalence in the rats. ADMA levels were positively correlated with Hcy levels, and both of them were negatively correlated with e NOS and NO. The present study demonstrated that ADMA which inhibited e NOS, reduced NO production, and interacted with Hcy, leading to endothelial dysfunction and artherosclerosis progressing possibly。With supplementation of both folic acid and vitamin B12, the level of ADMA and Hcy were able to be decreased significantly, and sequential improvement of the endothelial function and endothelium dependent vasodilatation, which was propitious to antiartherosclerosis. These findings provided a novel target for pharmacotherapy of cerebral infarction. Compared with the group added folic acid and vitamin B12,the ADMA and Hcy levels of the group added folicacid,vitamin B12 and probucol were lower, while the e NOS and NO levels were higher. With supplementation of both folic acid, vitamin B12 and probucol, the level of ADMA and Hcy were able to be decreased significantly, and sequential improvement of the endothelial function and endothelium dependent vasodilatation, which was propitious to antiartherosclerosis. |
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