1. Voltage-dependent N-type Ca2+ channels in endothelial cells contribute to oxidative stress-related endothelial dysfunction induced by angiotensin II in mice
- Author
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Caroline Sunggip, Shota Saiki, Shizuka Aritomi, Katsuya Hirano, Tatsuya Ishikawa, Motohiro Nishida, Koichiro Kuwahara, Yasuo Mori, Shokei Kim-Mitsuyama, and Eri Harada
- Subjects
medicine.medical_specialty ,Dihydropyridines ,Endothelium ,Vasodilator Agents ,Biophysics ,Vasodilation ,Aorta, Thoracic ,Blood Pressure ,medicine.disease_cause ,Biochemistry ,Mice ,Calcium Channels, N-Type ,Vascular relaxation ,omega-Conotoxin GVIA ,Internal medicine ,Renin–angiotensin system ,medicine ,Animals ,Endothelial dysfunction ,Molecular Biology ,Voltage-dependent calcium channel ,Dose-Response Relationship, Drug ,Chemistry ,Angiotensin II ,Macrophages ,Hemodynamics ,Cell Biology ,Cilnidipine ,medicine.disease ,Calcium Channel Blockers ,Oxidative Stress ,medicine.anatomical_structure ,Endocrinology ,Hypertension ,cardiovascular system ,Calcium ,Amlodipine ,Endothelium, Vascular ,Reactive Oxygen Species ,N-type Ca2+ channel ,Oxidative stress ,Biomarkers ,medicine.drug - Abstract
N-type voltage-dependent Ca2+channels (VDCCs), expressed predominantly in the nervous system, play pivotal roles in sympathetic regulation of the circulatory system. Although N-type VDCCs are also reportedly expressed in the vasculature, their pathophysiological role is obscure. We demonstrated that oxidative stress-related endothelial dysfunction induced by angiotensin (Ang) II is suppressed in mice lacking the N-type VDCC α1B subunit (Cav 2.2). Impairment of endothelium-dependent relaxation of the thoracic aorta observed following Ang II treatment in wild-type (WT) mice was significantly attenuated in the Ang II-treated Cav 2.2-deficient mice, despite the comparable increase of the blood pressure in the two groups of mice. The thoracic aorta of the Cav 2.2-deficient mice showed a smaller positive area of oxidative stress markers as compared to the WT mice. The Ang II-induced endothelial dysfunction was also suppressed by cilnidipine, an L/N-type VDCC blocker, but not by amlodipine, an L-type VDCC blocker; however, this unique effect of cilnidipine was completely abolished in the Cav 2.2-deficient mice. Furthermore, selective inhibition of N-type VDCCs by ω-conotoxin GVIA dramatically suppressed the production of reactive oxygen species (ROS) as well as agonist-induced Ca2+ influx in the vascular endothelial cells. These results suggest that N-type VDCCs expressed in the vascular endothelial cells contribute to ROS production and endothelial dysfunction observed in Ang II-treated hypertensive mice.
- Published
- 2013
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