Flashcards
Drugs on vascular smooth muscle
Cards in this deck (15)
- 1What is Darcy's Law?Flow = Change in pressure / resistance
- 2What is the key point of Poiseuille's Law?A small change in radius causes a large change in resistance.
- 3What is vascular tone?A balance between sympathetic constriction and dilatation caused by the NO pathway.
- 4Name 5 things that cause vasoconstriction.1. Neurotransmitters (NA)
2. Adrenaline
3. Endothelin-1
4. Vasopressin (ADH)
5. Angiotensin II - 5Which pathway do each of these use?Gq/11
- 6What is the result of this?Levels of Ca++ increase, so more Ca-Calmodulin complexes form which phosphorylate the myosin light chain using MLCK, allowing more cross-bridge formation.
- 7What is endothelin-1?A substance released from endothelial cells onto ETa receptors which causes vasoconstriction
- 8How do vasodilators work?They decrease Ca++ levels in VSMCs by blocking receptors for neurotransmitters and hormones and blocking VDCCs.
- 9Other mediators can stimulate vasodilation another way, via NO. What mediators can do this?ACh, histamine, bradykinin.
- 10Where do they act?On the endothelium
- 11How does NO cause vasodilation?NO enters VSMCs and activates Guanylyl Cyclase enzyme to produce cGMP and PKG. These cause decreased Ca++ levels and therefore dilatation.
- 12What are the 2 front-line treatments for hypertension?1. AT1 receptor antagonists (e.g. losartan) - prevents AngII binding to receptor.
2. ACE inhibitors (e.g. enalapril) - prevents AngI becoming AngII. - 13What other 2 drugs can be used to treat hypertension?1. VDCC blockers (e.g. Nifedipine)
2. Alpha-1 receptor antagonists (e.g. Prazosin) - 14What drug could be used to treat angina?Nitrates (e.g. glyceryl trinitrate [GTN]) to give NO and cause dilatation
- 15What is Viagra and how does it cause vasodilatation?PDE5 inhibitor, which prevents the breakdown of cGMP so the effects of NO can last longer
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- Degree CVS1 Flashcards on Drugs on vascular smooth muscle, created by Hannah Tribe on 06/05/2014.
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- Hannah Tribe
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