| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
1 Department of Cell and Molecular Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
* To whom correspondence should be addressed. E-mail: sfellner{at}med.unc.edu.
In afferent arteriolar vascular smooth muscle cells (VSMC), angiotensin II (Ang II) induces a rise in cytosolic Ca2+ ([Ca2+]i) via inositol trisphosphate receptor (IP3R) stimulation and by activation of the adenine diphosphate ribose (ADPR) cyclase to form cyclic ADPR, which sensitizes the ryanodine receptor (RyR) to Ca2+. We hypothesize that Ang II stimulation of NAD(P)H oxidases leads to the formation of superoxide anion (.O2 -), which, in turn, activates ADPR cyclase. Afferent arterioles were isolated from rat kidney with the magnetized microsphere and sieving technique and loaded with fura-2 to measure [Ca2+]i . Ang II rapidly increased [Ca2+]i by 124 ± 12 nM. In the presence of apocynin, a specific inhibitor of NAD(P)H oxidase assembly, the [Ca2+]i response was reduced to 35 ± 5 nM (P < 0.01). Tempol, a superoxide dismutase (SOD) mimetic, did not alter the [Ca2+]i response to Ang II at a concentration of 10-4 M (99 ± 12 nM), but 10- 3 M tempol reduced the response to 32 ± 3 nM (P < 0.01). Addition of nicotinamide, an inhibitor of ADPR cyclase, to apocynin or tempol (10-3 M) resulted in no further inhibition. Measurement of superoxide production with the fluorescent probe tempo 9- AC showed that Ang II caused an increase of 48 ± 20 arbitrary units; apocynin or diphenyl iodonium (an inhibitor of flavoprotein oxidases) inhibited the response by 94%. Hydrogen peroxide (H2O2) was studied at physiologic (10-7 M) and higher concentrations. In the presence of H2O2 (10-7 M) neither baseline [Ca2+]i nor the response to Ang II were altered (125 ± 15 nM), whereas H2O2 (10-6 and 10-5 M) inhibited the [Ca2+]i response to Ang II by 35 and 46%, respectively. We conclude that Ang II rapidly activates NAD(P)H oxidases of afferent arterioles, leading to the formation of .O2 -, which then stimulates ADPR cyclase to form cADPR. cADPR, by sensitizing the RyR to Ca2+, augments the Ca2+ response (calcium- induced calcium release) initiated by activation of the IP3R.
This article has been cited by other articles:
|
|
 |
|
  X.-F. Zhang and P. Forscher Rac1 Modulates Stimulus-evoked Ca2+ Release in Neuronal Growth Cones via Parallel Effects on Microtubule/Endoplasmic Reticulum Dynamics and Reactive Oxygen Species Production Mol. Biol. Cell, August 15, 2009; 20(16): 3700 - 3712. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Carlstrom, E. Y. Lai, Z. Ma, A. Patzak, R. D. Brown, and A. E. G. Persson Role of NOX2 in the regulation of afferent arteriole responsiveness Am J Physiol Regulatory Integrative Comp Physiol, January 1, 2009; 296(1): R72 - R79. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. E. Striker, F. Praddaude, O. Alcazar, S. W. Cousins, and M. E. Marin-Castano Regulation of angiotensin II receptors and extracellular matrix turnover in human retinal pigment epithelium: role of angiotensin II Am J Physiol Cell Physiol, December 1, 2008; 295(6): C1633 - C1646. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. L. Thai and W. J. Arendshorst ADP-ribosyl cyclase and ryanodine receptors mediate endothelin ETA and ETB receptor-induced renal vasoconstriction in vivo Am J Physiol Renal Physiol, August 1, 2008; 295(2): F360 - F368. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Satriano, R. Cunard, O. W. Peterson, T. Dousa, F. B. Gabbai, and R. C. Blantz Effects on kidney filtration rate by agmatine requires activation of ryanodine channels for nitric oxide generation Am J Physiol Renal Physiol, April 1, 2008; 294(4): F795 - F800. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Just, C. L. Whitten, and W. J. Arendshorst Reactive oxygen species participate in acute renal vasoconstrictor responses induced by ETA and ETB receptors Am J Physiol Renal Physiol, April 1, 2008; 294(4): F719 - F728. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. K. Fellner and W. J. Arendshorst Angiotensin II-stimulated Ca2+ entry mechanisms in afferent arterioles: role of transient receptor potential canonical channels and reverse Na+/Ca2+ exchange Am J Physiol Renal Physiol, January 1, 2008; 294(1): F212 - F219. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. L. Thai, S. K. Fellner, and W. J. Arendshorst ADP-ribosyl cyclase and ryanodine receptor activity contribute to basal renal vasomotor tone and agonist-induced renal vasoconstriction in vivo Am J Physiol Renal Physiol, October 1, 2007; 293(4): F1107 - F1114. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. K. Fellner and W. J. Arendshorst Voltage-gated Ca2+ entry and ryanodine receptor Ca2+-induced Ca2+ release in preglomerular arterioles Am J Physiol Renal Physiol, May 1, 2007; 292(5): F1568 - F1572. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Z. Wang, I. Armando, L. D. Asico, C. Escano, X. Wang, Q. Lu, R. A. Felder, C. G. Schnackenberg, D. R. Sibley, G. M. Eisner, et al. The elevated blood pressure of human GRK4{gamma} A142V transgenic mice is not associated with increased ROS production Am J Physiol Heart Circ Physiol, May 1, 2007; 292(5): H2083 - H2092. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Just, A. J. M. Olson, C. L. Whitten, and W. J. Arendshorst Superoxide mediates acute renal vasoconstriction produced by angiotensin II and catecholamines by a mechanism independent of nitric oxide Am J Physiol Heart Circ Physiol, January 1, 2007; 292(1): H83 - H92. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. K. Fellner and W. Arendshorst Endothelin-A and -B receptors, superoxide, and Ca2+ signaling in afferent arterioles Am J Physiol Renal Physiol, January 1, 2007; 292(1): F175 - F184. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. M. Touyz Mitochondrial Redox Control of Matrix Metalloproteinase Signaling in Resistance Arteries Arterioscler Thromb Vasc Biol, April 1, 2006; 26(4): 685 - 688. [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
