Role of phospholamban in NO/EDRF-induced relaxation in rat aorta.
The role of endothelium-derived nitric oxide (NO) to cause smooth muscle phospholamban (PLB) phosphorylation was studied in the isolated perfused rat aorta precontracted with norepinephrine using a back-phosphorylation technique. NO-induced relaxation was associated with increased PLB-phosphorylation while norepinephrine as such was ineffective. Removal of endothelium significantly reduced PLB-phosphorylation in indomethacin treated vessels. Stimulation of NO-formation by ATP augmented PLB-phosphorylation in intact vessels but was ineffective in denuded aortas. The results indicate that PLB-phosphorylation of vascular smooth muscle plays an important role in mediating NO-dependent relaxation by enhancing Ca(++)-uptake into sarcoplasmic reticulum.
Karczewski
P
P
Institute of Physiology I, University of Düsseldorf, Germany.
Kelm
M
M
Hartmann
M
M
Schrader
J
J
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000502:physiology; D002135:Calcium-Binding Proteins / Q000378:metabolism / Q000502:physiology*; D004730:Endothelium, Vascular / Q000378:metabolism / Q000502:physiology; D009119:Muscle Contraction / Q000187:drug effects; D009126:Muscle Relaxation / Q000187:drug effects / Q000502:physiology*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D009569:Nitric Oxide / Q000096:biosynthesis / Q000378:metabolism* / Q000494:pharmacology / Q000502:physiology*; D009638:Norepinephrine / Q000494:pharmacology; D010761:Phosphorus Radioisotopes; D010766:Phosphorylation; D051381:Rats; D000099211:Phospholamban
D000255:Adenosine Triphosphate; D002135:Calcium-Binding Proteins; D009569:Nitric Oxide; D009638:Norepinephrine; D010761:Phosphorus Radioisotopes; D000099211:Phospholamban