Korean J Thorac Cardiovasc Surg.  2013 Feb;46(1):14-21. 10.5090/kjtcs.2013.46.1.14.

Antioxidant Effect of Captopril and Enalapril on Reactive Oxygen Species-Induced Endothelial Dysfunction in the Rabbit Abdominal Aorta

• Kim JH
• Kim H
• Kim YH
• Chung WS
• Suh JK
• Kim SJ

• KMID: 1427820
• DOI: http://doi.org/10.5090/kjtcs.2013.46.1.14

Abstract

BACKGROUND
Reactive oxygen species (ROS) are known to be related to cardiovascular diseases. Many studies have demonstrated that angiotensin-converting enzyme inhibitors have beneficial effects against ROS. We investigated the antioxidant effect of captopril and enalapril in nitric oxide mediated vascular endothelium-dependent relaxations.
MATERIALS AND METHODS
Isolated rabbit abdominal aorta ring segments were exposed to ROS by electrolysis of the organ bath medium (Krebs-Henseleit solution) after pretreatment with various concentrations (range, 10-5 to 3x10-4 M) of captopril and enalapril. Before and after electrolysis, the endothelial function was measured by preconstricting the vessels with norepinephrine (10-6 M) followed by the cumulative addition of acetylcholine (range, 3x10-8 to 10-6 M). The relevance of the superoxide anion and hydrogen peroxide scavenging effect of captopril and enalapril was investigated using additional pretreatments of diethyldithiocarbamate (DETCA, 0.5 mM), an inhibitor of Cu/Zn superoxide dismutase, and 3-amino-1,2,4-triazole (3AT, 50 mM), an inhibitor of catalase.
RESULTS
Both captopril and enalapril preserved vascular endothelium-dependent relaxation after exposure to ROS in a dose-dependent manner (p<0.0001). Pretreatment with DETCA attenuated the antioxidant effect of captopril and enalapril (p<0.0001), but pretreatment with 3AT did not have an effect.
CONCLUSION
Both captopril and enalapril protect endothelium against ROS in a dose-dependent fashion in isolated rabbit abdominal aortas. This protective effect is related to superoxide anion scavenging.

Keyword

Reactive oxygen species; Angiotensin-converting enzyme inhibitors; Captopril; Enalapril; Vasodilation

MeSH Terms

Acetylcholine
Amitrole
Angiotensin-Converting Enzyme Inhibitors
Antioxidants
Aorta, Abdominal
Baths
Captopril
Cardiovascular Diseases
Ditiocarb
Electrolysis
Enalapril
Endothelium
Estradiol
Hydrogen Peroxide
Nitric Oxide
Norepinephrine
Oxygen
Reactive Oxygen Species
Superoxide Dismutase
Superoxides
Vasodilation
Acetylcholine
Amitrole
Angiotensin-Converting Enzyme Inhibitors
Antioxidants
Captopril
Ditiocarb
Enalapril
Estradiol
Hydrogen Peroxide
Nitric Oxide
Norepinephrine
Oxygen
Reactive Oxygen Species
Superoxide Dismutase
Superoxides