Related Experiment Videos
Antiperoxidative actions of calcium antagonists and atherogenesis
1Department of Medicine, Baylor College of Medicine, Houston 77030.
Abstract:
Recent experimental and clinical studies suggest that structurally disparate calcium channel blockers retard the progression of atherosclerosis. However, mechanisms of action by which calcium blockers exert their antiatherosclerotic effects have not been completely elucidated. Formation of atherosclerotic lesions involves cells (macrophages, endothelial cells, and platelets) not expressing voltage-dependent (L-type) calcium channels, the major drug receptors for calcium channel blockers. Therefore, it is possible that these drugs act by non-L-type channel mechanisms. Recent reports indicate that nifedipine, verapamil, and diltiazem exert antiperoxidative effects on membrane lipids. It has been suggested that antiperoxidants such as probucol and butylated hydroxytoluene (BHT) exert antiatherosclerotic effects by preventing oxidation of low-density lipoprotein (LDL), a modification thought to confer atherogenic properties to the lipoprotein. Therefore, the beneficial effects of calcium channel blockers might be related to their antiperoxidative activity.
Insights
Calcium channel blockers may slow atherosclerosis by preventing lipid peroxidation, a mechanism independent of their effects on L-type calcium channels. This antiperoxidative activity offers a novel therapeutic insight.
Area of Science:
- Cardiovascular Research
- Pharmacology
- Biochemistry
Background:
- Calcium channel blockers (CCBs) show promise in retarding atherosclerosis progression.
- The exact antiatherosclerotic mechanisms of CCBs remain unclear.
- Atherosclerosis involves cells lacking L-type calcium channels, suggesting non-channel-related actions.
Purpose of the Study:
- To investigate the potential non-L-type channel mechanisms of CCBs in atherosclerosis.
- To explore the antiperoxidative activity of CCBs as a contributing factor to their antiatherosclerotic effects.
Main Methods:
- Review of recent experimental and clinical studies on CCBs and atherosclerosis.
- Analysis of literature regarding CCB effects on membrane lipid peroxidation.
- Comparison of CCB antiperoxidative activity with known antioxidants like probucol and butylated hydroxytoluene (BHT).
Main Results:
- Nifedipine, verapamil, and diltiazem demonstrate antiperoxidative effects on membrane lipids.
- Antioxidants like probucol and BHT are known to prevent low-density lipoprotein (LDL) oxidation, a key step in atherogenesis.
- CCBs' antiperoxidative action may be linked to preventing LDL modification.
Conclusions:
- The antiatherosclerotic benefits of CCBs might stem from their antiperoxidative properties.
- This suggests a novel mechanism of action for CCBs, potentially independent of their primary L-type calcium channel blockade.
- Further research is warranted to confirm the role of antiperoxidation in CCB-mediated cardiovascular protection.