Martinez Marcio L L, Rizzi Elen, Castro Michele M, Fernandes Karla, Bendhack Lusiane M, Gerlach Raquel F, Tanus-Santos Jose E
Department of Pharmacology, Faculty of Medicine of Ribeirao Preto, Brazil.
Eur J Pharmacol. 2008 Dec 3;599(1-3):110-6. doi: 10.1016/j.ejphar.2008.10.007. Epub 2008 Oct 10.
Abnormal matrix metalloproteinases (MMPs) activity causes cardiovascular diseases. Because hyperglycemia increase MMPs activities through increased oxidative stress, we hypothesized that antioxidant effects produced by lercanidipine could attenuate the increases in MMP-2 expression/activity in diabetic rats. Control and diabetic (alloxan-induced diabetes) rats received lercanidipine 2.5 mg/kg/day (or tap water) starting three weeks after alloxan (or vehicle) injections. Blood pressure was monitored weekly. After six weeks of treatment, vascular reactivity and structural changes were assessed in aortic rings. MMP-2 levels were determined by gelatin zymography, and MMP-2/tissue inhibitor of metalloproteinases (TIMP)-2 mRNA levels were determined by quantitative real time RT-PCR. Plasma thiobarbituric acid reactive substances concentrations were determined by fluorimetry. Lercanidipine produced antihypertensive effects (201+/-5 vs. 163+/-7 mm Hg in diabetic rats untreated and treated with lercanidipine, respectively; P<0.01) and reversed the impairment in endothelium-dependent vasorelaxation in diabetic rats. Increased MMP-2 and Pro-MMP-2 levels were found in the aortas of diabetic rats (both P<0.001). Lercandipine attenuated the increases in oxidative stress and in MMP-2 (both P<0.05). While diabetes induced no major structural changes, it caused a 16-fold increase in the ratio of MMP-2/TIMP-2 mRNA expression, which was completely reversed by lercanidipine (both P<0.001). These results show that antioxidant and beneficial vascular effects produced by lercanidipine in diabetic rats are associated with reversion of the imbalance in vascular MMP-2/TIMP-2 expression.
异常的基质金属蛋白酶(MMPs)活性会引发心血管疾病。由于高血糖通过增加氧化应激来提高MMPs活性,我们推测乐卡地平产生的抗氧化作用可能会减弱糖尿病大鼠体内MMP - 2表达/活性的增加。对照组和糖尿病(四氧嘧啶诱导的糖尿病)大鼠在注射四氧嘧啶(或赋形剂)三周后开始接受2.5 mg/kg/天的乐卡地平(或自来水)。每周监测血压。治疗六周后,评估主动脉环的血管反应性和结构变化。通过明胶酶谱法测定MMP - 2水平,通过定量实时RT - PCR测定MMP - 2/金属蛋白酶组织抑制剂(TIMP)- 2 mRNA水平。通过荧光法测定血浆硫代巴比妥酸反应性物质浓度。乐卡地平产生了降压作用(未治疗的糖尿病大鼠和接受乐卡地平治疗的糖尿病大鼠的血压分别为201±5 vs. 163±7 mmHg;P<0.01),并逆转了糖尿病大鼠内皮依赖性血管舒张功能的损害。在糖尿病大鼠的主动脉中发现MMP - 2和前MMP - 2水平升高(均P<0.001)。乐卡地平减弱了氧化应激和MMP - 2的增加(均P<0.05)。虽然糖尿病未引起主要的结构变化,但它导致MMP - 2/TIMP - 2 mRNA表达比值增加了16倍,而乐卡地平完全逆转了这一变化(均P<0.001)。这些结果表明,乐卡地平在糖尿病大鼠中产生的抗氧化和有益的血管作用与血管MMP - 2/TIMP - 2表达失衡的逆转有关。