Cyclic ADP-ribose stimulates sarcoplasmic reticulum calcium release in porcine coronary artery smooth muscle.
Cyclic ADP-ribose (cADPR) was shown to induce calcium release from the endoplasmic reticulum via ryanodine-sensitive pathways. In smooth muscle, two pathways for calcium release from the sarcoplasmic reticulum (SR) have been previously demonstrated: D-myo-inositol 1, 4, 5-trisphosphate-gated and ryanodine-gated. However, evidence for cADPR as a regulator for SR Ca2+ release in smooth muscle is lacking. We used permeabilized porcine coronary artery smooth muscle cells to directly examine the stimulation of SR Ca2+ release by cADPR. The results provide direct evidence that cADPR stimulates SR Ca2+ release and that this response is not inhibited by heparin, by depletion of the caffeine-sensitive Ca2+ pool, or by blockade or ryanodine receptors. These results indicate a novel mechanism for Ca2+ release from the SR of vascular smooth muscle.
Kannan
M S
MS
Department of Veterinary Pathobiology, University of Minnesota, St. Paul 55108, USA.
Fenton
A M
AM
Prakash
Y S
YS
Sieck
G C
GC
D000246:Adenosine Diphosphate Ribose / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D001158:Arteries / Q000166:cytology / Q000378:metabolism; D002110:Caffeine / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D003331:Coronary Vessels / Q000166:cytology / Q000378:metabolism*; D036563:Cyclic ADP-Ribose; D006493:Heparin / Q000494:pharmacology; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000378:metabolism*; D012433:Ryanodine / Q000494:pharmacology; D012519:Sarcoplasmic Reticulum / Q000187:drug effects / Q000378:metabolism*; D013552:Swine
D036563:Cyclic ADP-Ribose; D012433:Ryanodine; D000246:Adenosine Diphosphate Ribose; D002110:Caffeine; D006493:Heparin; D002118:Calcium