Med Chem Treatment of HTN: Nitrates and misc. Vasodilators
Terms
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- What is nitric oxide?
- An intracellular and intercellular messenger
- How is nitric oxide formed?
- product of a reaction catalyzed by endothelial nitric oxide synthase (eNOS) substrate being L-arginine
- When is nitric oxide produced in the cardiovascular system?
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In response to:
1)Pharmacological control (bradykinin, histamine, and acetylcholine on endothelium)
2)Hypoxia
3)Stress (pressure on vessels) - What is the "story" of nitric oxide?
- Increase in biosynthesis of NO -> increased [NO] -> Activates enzyme guanylate cyclase -> catalyzes the conversion of GTP to cGMP -> increases [cGMP]-> elevated levels of cGMP intracellularly prevents the Ca++ channel from opening -> decreases [Ca++] -> not enough Ca++ to allow for vascular contraction (smooth muscle) -> decreased peripheral resistance and increased delivery of oxygen to the myocardial tissues
- What is the end result of Nitric oxide mechanism?
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Angina -> increases O2 to heart via vasodilation
HTN -> decrease peripheral resistance via vasodilation - What is the influence of CCBs on endogenous NO production?
- Promote release of NO from vascular endothelium
- What is the influence of ACE inhibitors on endogenous NO production?
- Bradykinin stimulates endothelium to relase vasodilators including NO
- What is the influence of HMG CoA Reductase Inhibitors on endogenous NO production?
- Stabilize nitric oxide synthetase, leads to increase in NO production
- What is the MOA of phosphodiesterase inhibitors?
- Increases cAMP which relaxes smooth muscle and contracts cardiac muscle
- What is the name of the natural product derived from opium?
- Papaverine
- What are the MOAs of Hydralazine?
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1) Activator of guanylate cyclase
2) Interferes with calcium entry and relase from intracellular stores - What are the MOAs of Dipyridamole?
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1) Adenosine deaminase inhibitor (adenosine is an inhibitor of PDE)
2)Phosphodiesterase inhibitor