Endothelial dysfunction, hypertension and atherosclerosis. A review of the effects of lacidipine

Treatment effect of lacidipine and amlodipine on clinic and ambulatory blood pressure and arteria stiffness in a randomised double-blind trial

PURPOSE

In a randomised, double-blind trial, we investigated effects of lacidipine on clinic and ambulatory blood pressure (BP) and arterial stiffness in patients with mild-to-moderate hypertension, as compared with amlodipine.

MATERIALS AND METHODS

Previously untreated and treated patients (n = 269, 50-80 years of age) with clinic hypertension (a clinic systolic/diastolic BP 140-180/<110 mmHg and <160/100 mmHg, respectively) were randomly assigned to double-dummy treatment with lacidipine (4-6 mg/day) or amlodipine (5-7.5 mg/day) for 20 weeks. The primary efficacy variable was the change in 24-h ambulatory systolic BP at 20 weeks of treatment. Arterial stiffness was measured as brachial-ankle pulse wave velocity (PWV).

RESULTS

After 20 weeks of treatment, 24-h systolic BP decreased from 141.3 ± 14.0 and 138.3 ± 12.8 mmHg at baseline, respectively, in the lacidipine (n = 134) and amlodipine groups (n = 135), by a least square mean (±SE) change of 15.2 ± 1.3 and 15.5 ± 1.3 mmHg, respectively, with a between-group difference (95% confidence interval [CI]) of 0.3 mmHg (-3.4 to 4.1, p = 0.86). Similar results were observed for other ambulatory BP components and clinic BP. Clinic and ambulatory pulse rate did not significantly change in either group (p ≥ 0.21). PWV decreased significantly (p < 0.001) from baseline in both groups, with a non-significant between-group difference of 0.24 m/s (p = 0.45). The incidence rate of adverse events was 30.3% (n = 40) and 27.5% (n = 36) in the lacidipine and amlodipine groups, respectively (p = 0.61). No serious adverse event occurred in the trial.

CONCLUSIONS

Lacidipine effectively lowers clinic and ambulatory BP in patients with mild-to-moderate hypertension and significantly improves arterial stiffness, similarly as amlodipine.

Cytoprotective Effects of Dinitrosyl Iron Complexes on Viability of Human Fibroblasts and Cardiomyocytes

Nitric oxide (NO) is an important signaling molecule that plays a key role in maintaining vascular homeostasis. Dinitrosyl iron complexes (DNICs) generating NO are widely used to treat cardiovascular diseases. However, the involvement of DNICs in the metabolic processes of the cell, their protective properties in doxorubicin-induced toxicity remain to be clarified. Here, we found that novel class of mononuclear DNICs with functional sulfur-containing ligands enhanced the cell viability of human lung fibroblasts and rat cardiomyocytes. Moreover, DNICs demonstrated remarkable protection against doxorubicin-induced toxicity in fibroblasts and in rat cardiomyocytes (H9c2 cells). Data revealed that the DNICs compounds modulate the mitochondria function by decreasing the mitochondrial membrane potential (ΔΨm). Results of flow cytometry showed that DNICs were not affected the proliferation, growth of fibroblasts. In addition, this study showed that DNICs did not affect glutathione levels and the formation of reactive oxygen species in cells. Moreover, results indicated that DNICs maintained the ATP equilibrium in cells. Taken together, these findings show that DNICs have protective properties in vitro. It was further suggested that DNICs may be uncouplers of oxidative phosphorylation in mitochondria and protective mechanism is mainly provided by the leakage of excess charge through the mitochondrial membrane. It is assumed that the DNICs have the therapeutic potential for treating cardiovascular diseases and for decreasing of chemotherapy-induced cardiotoxicity in cancer survivors.

Asymmetrical Dimethylarginine Inhibits Shear Stress–Induced Nitric Oxide Release and Dilation and Elicits Superoxide-Mediated Increase in Arteriolar Tone

l-arginine is the substrate used by NO synthase to produce the vasodilator NO. However, in several human diseases, such as hyperhomocysteinemia, diabetes mellitus, and hypertension, there is an increase in serum levels of methylated l-arginines, such as asymmetrical dimethylarginine (ADMA), which cannot be used by NO synthase to produce NO. Yet, the functional consequence of increased levels of ADMA on the vasomotor function of resistance vessels has not been delineated. We hypothesized that elevated levels of exogenous ADMA inhibit NO mediation of flow/shear stress-dependent dilation of isolated arterioles. In the presence of indomethacin, isolated arterioles from rat gracilis muscle (approximately 165 microm at 80 mm Hg) were incubated with ADMA (10(-4) mol/L), which eliminated the dilations to increases in intraluminal flow (control: from 164+/-5.4 to 188+/-3.8 microm versus ADMA: from 171+/-6.1 to 173+/-6.3 microm at 20 microL/min). ADMA did not affect dilations to nifedipine (10(-6) mol/L; control: 63.4+/-2%, ADMA: 65.8+/-3%) or 8-bromo cGMP (10(-4) mol/L; control: 51.2+/-2.1%, ADMA: 49.3+/-3.4%). In addition, ADMA elicited significant constriction of arterioles (from 173+/-17 microm to 138+/-16 microm at 80 mm Hg), which was prevented by previous incubation of arterioles with polyethylene-glycol (PEG) superoxide dismutase (SOD; 120 U/mL, control: 155+/-11 microm versus ADMA: 150+/-14 microm). Correspondingly, ADMA increased PEG-SOD reversible manner the production of vascular superoxide assessed by lucigenin-enhanced chemiluminescence and ethidium bromide fluorescence. Thus, increased levels of ADMA in various diseases could inhibit the regulation of arteriolar resistance by shear stress-induced release of NO and elicit superoxide-mediated increase in basal tone, both of which favor the development of hypertension.