Understanding Nitric Oxide and Vascular Smooth Muscle Regulation
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Explore the intricate mechanisms of NO synthesis, cGMP signaling, and vasodilation in vascular tissues. Learn how neural and intrinsic factors influence flow regulation in endothelium and VSM cells.
Understanding Nitric Oxide and Vascular Smooth Muscle Regulation
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Presentation Transcript
K 305 2 June 03
Regulation of Flow (Q) • Vascular Smooth Muscle Cells • Endothelium • Neural • Other Tissues • Intrinsic Factors
Regulation of Flow (Q) • Vascular Smooth Muscle Cells • Endothelium • Neural • Other Tissues • Intrinsic Factors
Regulation of Flow (Q) • Vascular Smooth Muscle Cells • Endothelium • Nitric Oxide • Endothelin • EDRF
Nitric Oxide • NO (EDRF) synthesized in endothelial cells by NOS • NOS stimulated by elevated [Ca2+]i • NOS converts arginine to NO • NO freely permeates out of endothelial cell into VSM • In VSM stimulates guanylyl cyclase increasing cGMP • cGMP activates PKG which stimulates: • SERCA (through phospholamban) and PMCA • Reduces [Ca2+]i - relaxation - VASODILATION • vasodilator drugs nitroglycerin and nitroprusside
Nitric Oxide – Ca2+ independent • Activates GC in VSM to stimulate PKG • PKG prevents Rho A from being activated • Prevents inhibition of MLC Phosphatase • Dephosporylates MLK • Induces relaxation in VSM - VASODILATION
Regulation of Flow (Q) • Vascular Smooth Muscle Cells • Endothelium • Nitric Oxide • Endothelin • EDRF
Regulation of Flow (Q) • Vascular Smooth Muscle Cells • Endothelium • Neural • Other Tissues • Intrinsic Factors
Regulation of Flow (Q) • Vascular Smooth Muscle Cells • Neural • NA – a adrenergic receptor • NA – b adrenergic receptor • ACh – muscarinic receptor
Regulation of Flow (Q) • Vascular Smooth Muscle Cells • Endothelium • Neural • Other Tissues • Intrinsic Factors