Pre-eclampsia (PE) is a hypertensive disorder of pregnancy and has been associated with placental growth restriction. The pre-eclamptic placenta releases free radicals to maternal circulation, thus increasing oxidative stress. An impaired redox state leads to reduction in circulating nitric oxide (NO) levels and activation of extracellular matrix metalloproteinases (MMPs). However, activation of MMPs induced by oxidative stress is still unclear in PE. Antioxidant effects have been demonstrated with the use of pravastatin. Therefore, we hypothesized that pravastatin protects against oxidative stress-induced activation of MMPs in a rat model of PE. The animals were divided into four groups: normotensive pregnant rats (Norm-Preg); pregnant rats treated with pravastatin (Norm-Preg + Prava); hypertensive pregnant rats (HTN-Preg); and hypertensive pregnant rats treated with pravastatin (HTN-Preg + Prava). The deoxycorticosterone acetate (DOCA) and sodium chloride (DOCA-salt) model was used to induce hypertension in pregnancy. Blood pressure, and fetal and placental parameters were recorded. The gelatinolytic activity of MMPs, NO metabolites and lipid peroxide levels were also determined. Endothelium function was also examined. Pravastatin attenuated maternal hypertension, prevented placental weight loss, increased NO metabolites, inhibited increases in lipid peroxide levels, and reduced the activity of MMP-2, and these effects were observed along with enhanced endothelium-derived NO-dependent vasodilation. The present results provide evidence that pravastatin protects against activation of MMP-2 induced by oxidative stress in pre-eclamptic rats. These findings may also involve improvement in endothelial function related to NO and antihypertensive effects of pravastatin, thus suggesting pravastatin as a therapeutic intervention for PE.
Preeclampsia (PE) is a hypertensive disorder of pregnancy and is associated with increases in soluble fms-like tyrosine kinase-1 (sFlt-1) and reductions in nitric oxide (NO) levels. Placental ischemia and hypoxia are hypothesized as initial pathophysiological events of PE. Nitrite (NO metabolite) may be recycled back to NO in ischemic and hypoxic tissues. Therefore, this study examined the sodium nitrite effects in an experimental model of PE. Pregnant rats received saline (Preg group) or sodium nitrite (Preg + Na-Nitrite group). Pregnant rats submitted to the placental ischemia received saline (RUPP group) or sodium nitrite (RUPP + Na-Nitrite group). Blood pressure, placental and fetal weights, and the number of pups were recorded. Plasma levels of NO metabolites and sFlt-1 were also determined. Vascular and endothelial functions were also measured. Blood pressure, placental and fetal weights, the number of pups, NO metabolites, sFlt-1 levels, vascular contraction, and endothelium-dependent vasodilation in the RUPP + Na-Nitrite rats were brought to levels comparable to those in Preg rats. In conclusion, sodium nitrite may counteract the reductions in NO and increases in sFlt-1 levels induced by the placental ischemia model of PE, thus suggesting that increased blood pressure and vascular and endothelial dysfunctions may be attenuated by sodium nitrite-derived NO.
Preeclampsia is a hypertensive disorder of pregnancy associated with elevated levels of soluble fms-like tyrosine kinase-1 (sFlt-1) and reduced nitric oxide (NO) bioavailability. Esomeprazole (ESO), a proton pump inhibitor (PPI) considered safe during pregnancy, has been proposed to reduce sFlt-1 levels in vitro. This study evaluated the effects of ESO in pregnant rats subjected to reduced uterine perfusion pressure (RUPP), a well-established model of preeclampsia. Pregnant rats received saline (Preg) or ESO (Preg+ESO), while RUPP-operated rats received saline (RUPP) or ESO (RUPP+ESO). At gestational day 21, maternal blood pressure was elevated in the Preg+ESO, RUPP, and RUPP+ESO groups compared with Preg, and ESO did not attenuate RUPP-induced hypertension. Fetal and placental weights were reduced in the RUPP group, whereas ESO increased placental weight in Preg+ESO and RUPP+ESO groups. Gastric pH was elevated by ESO, confirming reduced gastric acidity. Plasma sFlt-1 levels were increased in RUPP and significantly reduced by ESO in RUPP+ESO rats. NO metabolites (NOx) were decreased in RUPP but were unaffected by treatment. Endothelium-dependent relaxation was impaired in the RUPP and RUPP+ESO groups. In conclusion, ESO did not prevent hypertension or endothelial dysfunction, but reduced circulating sFlt-1, suggesting a partial modulatory effect on angiogenic imbalance in experimental preeclampsia.