The Protective Effects Of Bis Maltolato Oxovanadium On The Structure Of Aorta Of Spontenously Hypertensive Rats

Hypertension is a worldwide disease. The consequences rate ofhypertension are very high and has intimate relation to Cardio-Cerebral-Vascular disease. Now, most of people are damaged byhypertension. Even though many modern drugs have developed, butthe incidence of hypertension can't be controlled, instead which haselevated tendency year by year. The reason resulting to the situation isthat hypertension pathogenesis is unclear completly. Some researchdemonstrate that insulin resistance and diabetes mellitus type 2 all areMulti-genes diseases. Diabetes patients having more higher incidenceof hypertension shows that hypertension, diabetes and insulinresistance possess the common hereditary basis. Since the theory ofinsulin resistance syndrome was put forward, the possibility to treathypertension using insulin sensitizing agents to improve insulinsensitivity becomes a new stratagy. The contemporary medicine requests that the antihypertensiveagents should control the blood pressure effectively, in the same time,they could protect the target organs such as heart, kidney andcerebrum, which are harmed by long terms hypertensive situation.There are now six different classes of antihypertensive drugs suitablefor medicine therapy, that is diuretics, beta-blockers, ACE inhibitors,calcium channel blockers, angiotensin II receptor antagonists andalpha-blockers. These drugs can lower the higher blood pressure in thecertain degree. In fact, most of hypertension patients in the worldcouldn't be treated effectively and achieve the goal of blood pressurecontrolly. If all antihypertensive agents protecting target organseffectively require more clinical practice to confirm. Along withfurther understanding to the insulin resistance, more and morescholars pay attention to explore antihypertensive agents which canimprove insulin resistance.There are reports about applying insulin sensitizing agents to curesecondary hypertensive rats overseas. Our prior research has provedthat Bis (maltolo) oxovanadium (BMOV) could effectively controlblood pressure. There are seldom research on protection to targetorgans of hypertension. Our research is the first time applying BMOVto treat spontaneously hypertensive rats (SHR) and explore its aortasprotection effect on SHR.Methods:We selected thirty-six male spontaneously hypertensive rats,which were seven or eight weeks age. All rats were divided into threegroups randomly: SHR groups, BMOV groups and positive contrastgroups. Nifedipine was the positive contrast drugs. All drugs wereresolved to water to the rats. The whole experiment last eight weeks.During the experiment, we took every rat's blood pressure one timeper week. In the end of the experiment, we anesthetized the rats andput out their aortas which were made into samples, we applied lightand electron microscope to observe the rats' aortas histopathologychange.Results:After therapy of BMOV, the rat's blood pressure were loweredsince the first week of the experiment and at the third week reachedplatform time until to the eighth week. Nifedipine lowering the bloodpressure effect emerged in the first week. From blood pressure curvegraph, BMOV function of lowering blood pressure was more steady incontrast to Nifedipine.The histopathological changes (combined with light and electronmicroscope examination): The aortas of SHR shows: (1) Aortas wallare accumulation. (2) the endothelial cells and smooth muscle fibresappear irregular shape. (3)there are much more vacuoles inside of theendothelial cells. (4) under the endothelial level, there are wider spaceand much collagen and lipoidosis. (5) the smooth muscles showswelling and there are some collagen fibrils accumulating among thesmooth muscle cells. the aortas of SHR treated with BMOV andnifedipine show the features: (1) the endothelial cells show regularoutline and there are a few of vacuoles inside of the endothelial cells.(2) there are rarely seen collagen and lipoidosis in the space under theendothelial surface. (3) the smooth muscles appear the normal size andthere is almost no sign of collagen fibrils among the smooth musclecells. In contrast to SHR group rats, the difference is obviously.Conclusion:The aortas smooth muscle cells of rats in SHR group multipliedactively and the cells volume emerged compensatively magnified,which were relevant to serious pressure load. The sign of collagenfibrils accumulating under the endothelial level and among the smoothmuscle cells implied that blood vessel wall elasticity descend andsclerose. After therapy of BMOV and Nifedipine, the aortas wallaccumulation reduced and the endothelial cells appeared regularoutline. There were hardly shown collagen and lipoidosis accumulatedunder the endothelial layer. The outline of smooth muscle cellsbecame normal and the collagen was almost disappeared amongsmooth muscle cells. Our histopathologic results approved that bothBMOV and nifedipin have obviously protection effects on the aorta ofSHR. To concern the huge dose difference, BMOV may have moresignificant antihypertension and aortas protection effects.