Objective:To investigate the changes of calcium transport protein activities of aortic vascular smooth muscle cell in the progress of hypertension,evaluate the effects of irbesartan on them,then to elucidate the relationship between cell calcium transport protein and hypertension.Methods:Sixteen sixteen-week-old SHR were randomized into irbesartan treated group(IBT group,n=8)and distilled water group(DW group,n=8),and Wistar-Kyoto rats(WKY)as normal controls.Irbesartan and appropriate amounts of distilled water were administered respectively for 14 weeks by gavage.Blood pressure of caudal artery was examined before and after treatment,activities of Na+-K+-ATPase and Ca 2+-Mg 2+-ATPase of thoracic vascular aorta smooth muscle cell were measured.Results:Blood pressure in IBT group was much lower than that in DW group(129.17±3.71)vs(186.50±6.06),P<0.01).Compared with DW group,activities of Na+-K+-ATPase and Ca 2+-Mg 2+-ATPase of thoracic vascular aorta smooth muscle cell were remarkedly higher in both IBT group and WKY group(5.56±0.92)vs(2.91±0.56),P<0.01;(4.83±0.86)vs(2.76±0.43),P<0.01),(5.98±0.63)vs(2.91±0.56),P<0.01;(4.94±0.84)vs(2.76±0.43),P<0.01),while there was a slight difference between IBT group and WKY group(P>0.05).Activities of Na+-K+-ATPase and Ca 2-Mg 2+-ATPase of thoracic aorta smooth muscle cel were negatively relative to blood pressure(r=-0.446、r=-0.387,P<0.01).Conclusion:The changes of calcium transport protein activities of aortic vascular smooth muscle cell play an important role in the development of hypertension.Irbesartan may effectively inhibit the progress of hypertension by elevating calcium transport protein activities of vascular smooth muscel cell.
