Nitric oxide inhibits Ca(2+) mobilization through cADP-ribose signaling in coronary arterial smooth muscle cells.
The present study was designed to determine whether the cADP-ribose-mediated Ca(2+) signaling is involved in the inhibitory effect of nitric oxide (NO) on intracellular Ca(2+) mobilization. With the use of fluorescent microscopic spectrometry, cADP-ribose-induced Ca(2+) release from sarcoplasmic reticulum (SR) of bovine coronary arterial smooth muscle cells (CASMCs) was determined. In the alpha-toxin-permeabilized primary cultures of CASMCs, cADP-ribose (5 microM) produced a rapid Ca(2+) release, which was completely blocked by pretreatment of cells with the cADP-ribose antagonist 8-bromo-cADP-ribose (8-Br-cADPR). In intact fura 2-loaded CASMCs, 80 mM KCl was added to depolarize the cells and increase intracellular Ca(2+) concentration ([Ca(2+)](i)). Sodium nitroprusside (SNP), an NO donor, produced a concentration-dependent inhibition of the KCl-induced increase in [Ca(2+)](i), but it had no effect on the U-46619-induced increase in [Ca(2+)](i). In the presence of 8-Br-cADPR (100 microM) and ryanodine (10 microM), the inhibitory effect of SNP was markedly attenuated. HPLC analyses showed that CASMCs expressed the ADP-ribosyl cyclase activity, and SNP (1-100 microM) significantly reduced the ADP-ribosyl cyclase activity in a concentration-dependent manner. The effect of SNP was completely blocked by addition of 10 microM oxygenated hemoglobin. We conclude that ADP-ribosyl cyclase is present in CASMCs, and NO may decrease [Ca(2+)](i) by inhibition of cADP-ribose-induced Ca(2+) mobilization.
Yu
J Z
JZ
Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA.
Zhang
D X
DX
Zou
A P
AP
Campbell
W B
WB
Li
P L
PL
D036541:ADP-ribosyl Cyclase; D051997:ADP-ribosyl Cyclase 1; D000246:Adenosine Diphosphate Ribose / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors / Q000378:metabolism* / Q000494:pharmacology; D000818:Animals; D015703:Antigens, CD; D000943:Antigens, Differentiation / Q000187:drug effects / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D002417:Cattle; D002463:Cell Membrane Permeability / Q000187:drug effects; D002478:Cells, Cultured; D003331:Coronary Vessels / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D036563:Cyclic ADP-Ribose; D006162:Guanylate Cyclase / Q000037:antagonists & inhibitors; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D009244:NAD+ Nucleosidase / Q000187:drug effects / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism* / Q000494:pharmacology; D009712:Nucleotides, Cyclic / Q000378:metabolism / Q000494:pharmacology; D011189:Potassium Chloride / Q000494:pharmacology; D012519:Sarcoplasmic Reticulum / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D010738:Type C Phospholipases / Q000494:pharmacology; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014665:Vasodilator Agents / Q000494:pharmacology
D015703:Antigens, CD; D000943:Antigens, Differentiation; D009712:Nucleotides, Cyclic; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D036563:Cyclic ADP-Ribose; D000246:Adenosine Diphosphate Ribose; D009569:Nitric Oxide; D011189:Potassium Chloride; D010738:Type C Phospholipases; D036541:ADP-ribosyl Cyclase; D009244:NAD+ Nucleosidase; D051997:ADP-ribosyl Cyclase 1; D006162:Guanylate Cyclase; D002118:Calcium