| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Department of Emergency Medicine and 2 Institute for Environmental Medicine, Department of Biochemistry and 5 Biophysics and 6 Department of Physiology, University of Pennsylvania Medical Center, Philadelphia 19104; 3 Philadelphia Biomedical Research Institute, King of Prussia, Pennsylvania 19406; and 4 Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104
We hypothesized that elevated partial pressures of O2 would increase perivascular nitric oxide (·NO) synthesis. Rodents with O2- and ·NO-specific microelectrodes implanted adjacent to the abdominal aorta were exposed to O2 at partial pressures from 0.2 to 2.8 atmospheres absolute (ATA). Exposures to 2.0 and 2.8 ATA O2 stimulated neuronal (type I) NO synthase (nNOS) and significantly increased steady-state ·NO concentration, but the mechanism for enzyme activation differed at each partial pressure. At both pressures, elevations in ·NO concentration were inhibited by the nNOS inhibitor 7-nitroindazole and the calcium channel blocker nimodipine. Enzyme activation at 2.0 ATA O2 appeared to be due to an altered cellular redox state. Exposure to 2.8 ATA O2, but not 2.0 ATA O2, increased nNOS activity by enhancing nNOS association with calmodulin, and an inhibitory effect of geldanamycin indicated that the association was facilitated by heat shock protein 90. Infusion of superoxide dismutase inhibited ·NO elevation at 2.8 but not 2.0 ATA O2. Hyperoxia increased the concentration of ·NO associated with hemoglobin. These findings highlight the complexity of oxidative stress responses and may help explain some of the dose responses associated with therapeutic applications of hyperbaric oxygen.
neuronal nitric oxide synthase; heat shock protein 90; calmodulin; hyperbaric oxygen
This article has been cited by other articles:
|
|
 |
|
  H. D. Bauser-Heaton, J. Song, and H. G. Bohlen Cerebral microvascular nNOS responds to lowered oxygen tension through a bumetanide-sensitive cotransporter and sodium-calcium exchanger Am J Physiol Heart Circ Physiol, May 1, 2008; 294(5): H2166 - H2173. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Dainer, J. Nelson, K. Brass, E. Montcalm-Smith, and R. Mahon Short oxygen prebreathing and intravenous perfluorocarbon emulsion reduces morbidity and mortality in a swine saturation model of decompression sickness J Appl Physiol, March 1, 2007; 102(3): 1099 - 1104. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Hink, S. R. Thom, U. Simonsen, I. Rubin, and E. Jansen Vascular reactivity and endothelial NOS activity in rat thoracic aorta during and after hyperbaric oxygen exposure Am J Physiol Heart Circ Physiol, October 1, 2006; 291(4): H1988 - H1998. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. J. Goldstein, K. A. Gallagher, S. M. Bauer, R. J. Bauer, V. Baireddy, Z.-J. Liu, D. G. Buerk, S. R. Thom, and O. C. Velazquez Endothelial Progenitor Cell Release into Circulation Is Triggered by Hyperoxia-Induced Increases in Bone Marrow Nitric Oxide Stem Cells, October 1, 2006; 24(10): 2309 - 2318. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. P. Cabigas, J. Su, W. Hutchins, Y. Shi, R. B. Schaefer, R. F. Recinos, V. Nilakantan, E. Kindwall, J. A. Niezgoda, and J. E. Baker Hyperoxic and hyperbaric-induced cardioprotection: Role of nitric oxide synthase 3 Cardiovasc Res, October 1, 2006; 72(1): 143 - 151. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. R. Thom, V. M. Bhopale, O. C. Velazquez, L. J. Goldstein, L. H. Thom, and D. G. Buerk Stem cell mobilization by hyperbaric oxygen Am J Physiol Heart Circ Physiol, April 1, 2006; 290(4): H1378 - H1386. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F. Palm, D. G. Buerk, P.-O. Carlsson, P. Hansell, and P. Liss Reduced Nitric Oxide Concentration in the Renal Cortex of Streptozotocin-Induced Diabetic Rats: Effects on Renal Oxygenation and Microcirculation Diabetes, November 1, 2005; 54(11): 3282 - 3287. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. O Brubakk, D Duplancic, Z Valic, I Palada, A Obad, D Bakovic, U Wisloff, and Z Dujic A single air dive reduces arterial endothelial function in man J. Physiol., August 1, 2005; 566(3): 901 - 906. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. M. Denton, A. Shweta, R. L. Flower, and W. P. Anderson Predominant postglomerular vascular resistance response to reflex renal sympathetic nerve activation during ANG II clamp in rabbits Am J Physiol Regulatory Integrative Comp Physiol, October 1, 2004; 287(4): R780 - R786. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
