Comparative Effects of Azelnidipine and Other Ca2+-Channel Blockers on the Induction of Inducible Nitric Oxide Synthase in Vascular Smooth Muscle Cells

Abstract

Overproduction of nitric oxide by inducible nitric oxide synthase contributes to the progression of cardiovascular disease. We investigated the effects of azelnidipine and other Ca2+-channel blockers on nitric oxide production by cultured aortic smooth muscle cells isolated from Wistar rats and human umbilical vein endothelial cells (HUVECs), using the Griess reaction and oxyhemoglobin method. Release of lactic dehydrogenase (LDH) was measured to evaluate cell damage, and immunohistochemistry was performed to examine the expression of inducible nitric oxide synthase and nitrotyrosine protein. Azelnidipine and other Ca2+-channel blockers inhibited the release of nitric oxide induced by lipopolysaccharide plus interferon-gamma. Azelnidipine inhibited it most potently among the Ca2+-channel blockers tested (azelnidipine, amlodipine, nifedipine, diltiazem, verapamil, and nicardipine) at a concentration of 10 microM. Longer stimulation with these agents induced the expression of inducible nitric oxide synthase and nitrotyrosine, with an increase of lactic dehydrogenase release, whereas azelnidipine suppressed these changes. In human umbilical vein endothelial cells, azelnidipine enhanced basal nitric oxide production by endothelial nitric oxide synthase. In conclusion, azelnidipine potently inhibited the induction of inducible nitric oxide synthase and then nitric oxide production in vascular smooth muscle cells, while enhancing constitutive nitric oxide production by endothelial cells. Azelnidipine may inhibit nitrotyrosine expression and cell damage caused by overproduction of nitric oxide, suggesting a mechanism for its cardiovascular protective effect.

Azelnidipine Inhibits Msx2-Dependent Osteogenic Differentiation and Matrix Mineralization of Vascular Smooth Muscle Cells

“…There is a general consensus that 1,000 nmol/L CCB is considerably high but this concentration is relevant to a clinical setting because the tissue concentration of azelnidipine is higher than that in the plasma due to its high lipid solubility. 16) Second, we have not yet determined whether this effect is unique to azelnidipine, or if other third-generation DHP-based CCBs have similar effects. In particular, amlodipine is known to exert pleiotropic effects such as inhibition of platelet aggregation and stimulation synthesis, which are distinct from calcium channel antagonism, 14) and therefore its effect on the vascular calcification process should also be examined in future studies.…”

“…In fact, azel-nidipine is reported to cause longer relaxation of smooth muscle cells and more enhanced NO production in endothelial cells than other CCBs. 15,16) Furthermore, we have previously reported that azelnidipine down-regulates gene expression of molecular components of the renin-angiotensin-aldosterone system, 17) suggesting a novel mechanism for the vasoprotective and renoprotective effect of azelnidipine. Despite the potential beneficial effect of azelnidipine on vascular cells, it has not yet been determined whether azelnidipine inhibits the osteogenic differentiation of VSMCs and further development of vascular calcification.…”

Beneficial Effects of Combination Therapy with Olmesartan and Azelnidipine in Murine Polycystic Kidneys

“…CCBs are known to increase NO production through upregulation of eNOS [29,30] . The antioxidative action of a CCB also enhances NO production since NO is rapidly deactivated by ROS [31][32][33] .…”

Calcium Channel Blocker, Azelnidipine, Reduces Lipid Hydroperoxides in Patients with Type 2 Diabetes Independent of Blood Pressure

“…While DCCB is regarded to have anti-oxidative activity [7], azelnidipine is expected to have a larger anti-oxidative activity at its clinical dosage than other DCCBs [37]. In the present study, we evaluated the effectiveness of azelnidipine in terms of oxidative stress.…”