The Changes Of Serum Matrix Metalloproteinase -9 And Tissue Inhibitor Metalloproteinase-1 In Essential Hypertension

The Changes of Serum Matrix Metalloproteinase -9 and Tissue Inhibitor Metalloproteinase-1 in Essential HypertensionBackgroundRecently finds indicate that the remodeling of heart is related to not only the hypertrophy and apocity of myocardial cells, but also linked to the extracellular matrix which plays an important role in the arrangement of myocardial cells, contrctive harmony of myocardium and maintaining the geometry figure of left ventricle. The Matrix Metalloproteinases(MMPs)/ Tissue Inhibitor Metalloproteinases(TIMPs) system as a Zn2+-dependent proteinase play the determinant role in theregulation of collagen tissue turnover, which have the widely expression in cardiovascular diseases. The abnormity about metabolism of Matrix Metalloproteinase-9(MMP-9) in the patients with essential hypertension hasn't been explored in our country, so we measured the serum levels of MMP-9 and Tissue Inhibitor Metalloproteinase-1(TIMP-1) and tried to investigate the relationship between MMP-9/TIMP-1 and left ventricular hypertrophy(LVH) in essential hypertension.Methods40 patients with essential hypertension were arranged randomly, all accorded the hypertension diagnostic criterion of WHO/ISH. 28 healthy people acted ascontrol group. The additional factors which maybe elevate the levels of serum MMP-9 and TIMP-1 were excluded, such as rheumatoid arthritis, cancer, idiopathic pulmonary fibrosis, liver cirrhosis and heart failure. In addition, all patients had not the diabetes mellitus, coronary heart diease and hypertrophic myocardiopathy which could result in LVH. Serum samples each about 3ml were collected on an empty stomach in the morning and stored at -75 ?C for 2 months. Serum MMP-9 and TIMP-1 were determined by ELISA method according to the procedures of specification. Doppler echocardiography was performed in the patients. We measured the left ventricular mass with the Devereux and Reichek's equation according to the LA, LVDd, LVDs, IVST and PWT., then figured out the left ventricular mass index (LVMI) ,. The standard of LVH in male is LVMI≥120 g/m2 ,in female is LVMI ≥ 115g/m2. The software of SPSS 11.0 was been used in statistics analysis. Values were expressed as mean±SEM. Student's t tset for unpaired data was used to assess the statistical significance between hypertensive patients and normtensive control subjects and between hypertensive patients with LVH and without LVH. A value of P<0.05 was considered statistically significant.Results1. 11 cases were found LVH, 29 cases without LVH.2. Serum concentrations of MMP-9 was lower and serum levels of TIMP-1 was higher in hypertensive patients than in normotensive control subjects (296.38±159.23 ng.mL-1 vs 499.62±334.80 ng.mL-1, 355.99±114.95 ng.mL-1vs 205.45±38.77 ng.mL-1; P<0.001 and P<0.05 respectively).3. Serum concentrations of MMP-9 and TIMP-1 in hypertensive patients with or without LVH also had the same statistical significant as the result 2 when compared to the control group. No significant difference was observed between thepatients with LVH and those without LVH. But hypertensive patients with LVH exhibited higher values of serum TIMP-1 than hypertensive patients without LVH (491.27@ 75.03 ng.mL-1#298.47 @42.98 ng.mL-1, P<0.001).ConclusionsWe suggest that the activity of serum MMP-9 is low and its of serum TIMP-1 is high in hypertensive patients with or without LVH, and the increase in concentrations of serum TIMP-1 can reflect left ventricular hypertrophy of essential hypertension.