Cyclic adp-ribose stimulates sarcoplasmic reticulum calcium release
in porcine coronary artery smooth muscle.
Kannan, Mathur S., Alexis M. Fenton, Y. S. Prakash, and Gary C. Sieck.
Departments of Veterinary PathoBiology and Pediatrics, University
of Minnesota, St. Paul, MN 55108, and Departments of Anesthesiology
and Physiology & Biophysics, Mayo Foundation, Rochester, MN
55905
APStracts 2:0529H, 1995.
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- IP3-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 of ryanodine receptors. These results
indicate a novel mechanism for Ca2+ release from the SR of vascular
smooth muscle.
Received 5 September 1995; accepted in final form 13 November
1995.
APS Manuscript Number H837-5.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 8 December 95