| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Department of Anesthesiology, Baylor College of Medicine, Houston, Texas 77030
The present study was designed to evaluate the role of endothelial intracellular Ca2+ concentration ([Ca2+]i) in the difference between P2Y1- and P2Y2-mediated vasodilatations in cerebral arteries. Rat middle cerebral arteries were cannulated, pressurized, and luminally perfused. The endothelium was selectively loaded with fura 2, a fluorescent Ca2+ indicator, for simultaneous measurement of endothelial [Ca2+]i and diameter. Luminal administration of 2-methylthioadenosine 5'-triphosphate (2-MeS-ATP), an endothelial P2Y1 agonist, resulted in purely nitric oxide (NO)-dependent dilation and [Ca2+]i increases up to ~300 nM (resting [Ca2+]i = 145 nM). UTP, an endothelial P2Y2 agonist, resulted in dilations that were both endothelium-derived hyperpolarizing factor (EDHF)- and NO-dependent with [Ca2+]i increases to >400 nM. In the presence of NG-nitro-L-arginine-indomethacin to inhibit NO synthase and cyclooxygenase, UTP resulted in an EDHF-dependent dilation alone. The [Ca2+]i threshold for NO-dependent dilation was 220 vs. 340 nM for EDHF. In summary, the differences in the mechanism of vasodilatation resulting from stimulation of endothelial P2Y1 and P2Y2 purinoceptors result in part from differential [Ca2+]i responses. Consistent with this finding, these studies also demonstrate a higher [Ca2+]i threshold for EDHF-dependent responses compared with NO.
endothelium-derived hyperpolarizing factor; calcium; cerebral; nitric oxide; purinergic
This article has been cited by other articles:
|
|
 |
|
  D. X. Zhang, S. A. Mendoza, A. H. Bubolz, A. Mizuno, Z.-D. Ge, R. Li, D. C. Warltier, M. Suzuki, and D. D. Gutterman Transient Receptor Potential Vanilloid Type 4-Deficient Mice Exhibit Impaired Endothelium-Dependent Relaxation Induced by Acetylcholine In Vitro and In Vivo Hypertension, March 1, 2009; 53(3): 532 - 538. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. P. Marrelli, R. G. O'Neil, R. C. Brown, and R. M. Bryan Jr. PLA2 and TRPV4 channels regulate endothelial calcium in cerebral arteries Am J Physiol Heart Circ Physiol, March 1, 2007; 292(3): H1390 - H1397. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. M. Sokoya, A. R. Burns, C. T. Setiawan, H. A. Coleman, H. C. Parkington, and M. Tare Evidence for the involvement of myoendothelial gap junctions in EDHF-mediated relaxation in the rat middle cerebral artery Am J Physiol Heart Circ Physiol, July 1, 2006; 291(1): H385 - H393. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Andresen, N. I. Shafi, and R. M. Bryan Jr. Endothelial influences on cerebrovascular tone J Appl Physiol, January 1, 2006; 100(1): 318 - 327. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. A. Reading, S. Earley, B. J. Waldron, D. G. Welsh, and J. E. Brayden TRPC3 mediates pyrimidine receptor-induced depolarization of cerebral arteries Am J Physiol Heart Circ Physiol, May 1, 2005; 288(5): H2055 - H2061. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H.-L. Xu, S. Ye, V. L. Baughman, D. L. Feinstein, and D. A. Pelligrino The role of the glia limitans in ADP-induced pial arteriolar relaxation in intact and ovariectomized female rats Am J Physiol Heart Circ Physiol, January 1, 2005; 288(1): H382 - H388. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. D. Luykenaar, S. E. Brett, B. N. Wu, W. B. Wiehler, and D. G. Welsh Pyrimidine nucleotides suppress KDR currents and depolarize rat cerebral arteries by activating Rho kinase Am J Physiol Heart Circ Physiol, March 1, 2004; 286(3): H1088 - H1100. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. P. Marrelli, M. S. Eckmann, and M. S. Hunte Role of endothelial intermediate conductance KCa channels in cerebral EDHF-mediated dilations Am J Physiol Heart Circ Physiol, October 1, 2003; 285(4): H1590 - H1599. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. S. Sprague, J. J. Olearczyk, D. M. Spence, A. H. Stephenson, R. W. Sprung, and A. J. Lonigro Extracellular ATP signaling in the rabbit lung: erythrocytes as determinants of vascular resistance Am J Physiol Heart Circ Physiol, July 11, 2003; 285(2): H693 - H700. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. Erdos, A. W. Miller, and D. W. Busija Impaired endothelium-mediated relaxation in isolated cerebral arteries from insulin-resistant rats Am J Physiol Heart Circ Physiol, June 1, 2002; 282(6): H2060 - H2065. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. M. Golding, S. P. Marrelli, J. You, and R. M. Bryan Jr Endothelium-Derived Hyperpolarizing Factor in the Brain: A New Regulator of Cerebral Blood Flow? Stroke, March 1, 2002; 33(3): 661 - 663. [Full Text] [PDF]
|
|
|
|
|
|
L. A. Schildmeyer and R. M. Bryan Jr. Effect of NO on EDHF response in rat middle cerebral arteries Am J Physiol Heart Circ Physiol, February 1, 2002; 282(2): H734 - H738. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H.-L. Xu, D. L. Feinstein, R. A. Santizo, H. M. Koenig, and D. A. Pelligrino Agonist-specific differences in mechanisms mediating eNOS-dependent pial arteriolar dilation in rats Am J Physiol Heart Circ Physiol, January 1, 2002; 282(1): H237 - H243. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. Erdos, A. W. Miller, and D. W. Busija Impaired endothelium-mediated relaxation in isolated cerebral arteries from insulin-resistant rats Am J Physiol Heart Circ Physiol, June 1, 2002; 282(6): H2060 - H2065. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
