Effects of Atorvastatin and l-Arginine Treatments on Electrical Field Stimulation-mediated Relaxations in Pulmonary Arterial Rings of Monocrotaline-Induced Pulmonary Hypertensive Rats

Efficacy and Safety of Statins for Pulmonary Hypertension: A Meta-Analysis of Randomised Controlled Trials

BACKGROUND

Pulmonary hypertension (PH) is a serious disease, and treatment is a continuing challenge. Some in vitro and in vivo studies identified that statins were effective for PH. However, results of some randomised controlled trials (RCTs) have been controversial. The objective of our study was to clarify whether statins are effective and safe for pulmonary hypertension.

METHODS

We systematically searched for eligible RCTs from PubMed, EMBASE, Web of Science, and the Cochrane Library during January 2016. Two reviewers independently extracted data. Standard mean differences (SMDs) and weighted mean differences (WMDs) with 95% confidence intervals (CIs) were estimated for continuous data (exercise capacity cardiac, pulmonary arterial pressure (PAP), cardiac index, and low-density lipoprotein (LDL)). Risk ratios (RRs) were estimated for dichotomous data (adverse events and clinical deterioration).

RESULTS

A total of 496 patients from six RCTs were included. Low-density lipoprotein in the statin group decreased significantly compared with the placebo group (WMD = -22.79; 95% CI: -34.33 ∼ -11.24). However, we did not find a statistically significant effect on exercise capacity (SMD = 0.18; 95% CI: -0.34 - 0.71), PAP (WMD = -3.01; 95% CI: -8.68 - 2.65), or CI (WMD = -0.04; 95% CI: -0.15 - 0.23). Additionally, there was no difference between statins and placebo with respect to hepatic injury (RR: 1.12; 95% CI: 0.43 - 2.92), myalgia (RR: 0.81; 95% CI: 0.32 - 2.03), or clinical deterioration (RR: 0.98; 95% CI: 0.58 - 1.67).

CONCLUSIONS

Statin treatment appears to be safe but may have no effect on PH.

Role of nitric oxide in pathophysiology and treatment of pulmonary hypertension

Pulmonary hypertension is a condition characterized by vasoconstriction, vascular cell proliferation, inflammation, microthrombosis, and vessel wall remodelation. Pulmonary endothelial cells produce vasoactive substances with vasoconstrictive as well as vasodilatative effects. The imbalance of these endothelium-derived vasoactive substances induced by endothelial dysfunction is very important in the pathogenesis of PH. One of most important substances with vasodilatative effect is nitric oxide. We provide a comprehensive insight into role of NO in the pathgenesis of PH and discuss perspectives and challenges in PH therapy based on NO administration.

Naringenin adds to the protective effect of L-arginine in monocrotaline-induced pulmonary hypertension in rats: favorable modulation of oxidative stress, inflammation and nitric oxide

The present study was directed to investigate the possible modulatory effect of naringenin when co-administered with L-arginine in monocrotaline-induced pulmonary hypertension in rats. Pulmonary hypertension was induced by a single subcutaneous injection of monocrotaline (60 mg/kg). L-arginine (500 mg/kg) and naringenin (50 mg/kg) were orally administered daily, alone and in combination, for 3 weeks. Mean arterial blood pressure, electrocardiography and echocardiography were then recorded and rats were sacrificed and serum was separated for determination of total nitrate/nitrite level. Right ventricles and lungs were isolated for estimation of oxidative stress markers, tumor necrosis factor-alpha, total nitrate/nitrite and transforming growth factor-beta. Myeloperoxidase and caspase-3 activities in addition to endothelial and inducible nitric oxide synthase protein expression were also determined. Moreover, histological analysis of pulmonary arteries and cardiomyocyte cross-sectional area was performed. Combined therapy provided a significant improvement in L-arginine protective effect toward preserving hemodynamic changes and alleviating oxidative stress, inflammatory and apoptotic markers induced by monocrotaline treatment. Furthermore, combined therapy prevented monocrotaline-induced changes in endothelial and inducible nitric oxide synthase protein expression as well as histological analysis compared with either treatment alone. In conclusion, naringenin significantly adds to the protective effect of L-arginine in pulmonary hypertension induced by monocrotaline in rats.