Vasodilator Review

  1. Increasing cellular levels of cGMP or decreasing levels of intracellular Ca++ in smooth muscle causes...
    Smooth muscle relaxation.
  2. Two classes of drugs that cause increases in cGMP include...
    • Organic nitrates
    • PDE-5 inhibitors
  3. Two classes of drugs that cause decreases in intracellular Ca++ include...
    • CCBs
    • a1-adrenergic antagonists
  4. Which type of GPCR naturally causes increases in intracellular Ca++?
    G-alpha q
  5. True or False?

    Smooth muscle stores Ca++ intracellularly.
  6. Why do PDE inhibitors lead to increased levels of cGMP?
    PDEs break down cGMP.
  7. How does NO lead to increased levels of cGMP?
    NO activates guanylyl cyclase, which converts GTP to cGMP.
  8. Stabilization of smooth muscle depolarization causes...
    Smooth muscle relaxation.
  9. How do K+ channel agonists prevent smooth muscle depolarization and contraction?
    By increasing K+ efflux from a cell, the membrane potential hyperpolarizes as the inside of the cell becomes more negatively charged with respect to the outside. This prolongs or prevents the activation of voltage-gated calcium channels.
  10. Increased activity of myosin light chain kinase causes...
    Smooth muscle contraction.
  11. Increased leveks if cAMP lead to...
    Smooth muscle relaxation as mysoin light chain kinase is inactivated.
  12. How does increasing levels of cGMP cause smooth muscle relaxation?
    Increases dephosphorylation of myosin light chains by myosin light chain phosphatase.
  13. How does decreasing levels of intracellular Ca++ lead to smooth muscle relaxation?
    Decreases the activity of myosin light chain kinase.
  14. What is another term for "endothelial derived relaxing factor" (EDRF)?
    Nitric oxide. NO is produced from arginine, and is made naturally by vascular endothelium.
Card Set
Vasodilator Review
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