| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Departments of Veterinary Biomedical Sciences and Physiology, Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri 65211
The effect of cardiovascular
deconditioning on baroreflex control of the sympathetic nervous system
was evaluated after 14 days of hindlimb unloading (HU) or the control
condition. Rats were chronically instrumented with catheters and
sympathetic nerve recording electrodes for measurement of mean arterial
pressure (MAP) and heart rate (HR) and recording of lumbar (LSNA) or
renal (RSNA) sympathetic nerve activity. Experiments were conducted 24 h after surgery, with the animals in a normal posture. Baroreflex function was assessed using a logistic function that related HR and
LSNA or RSNA to MAP during infusion of phenylephrine and nitroprusside. Baroreflex influence on HR was not affected by HU. Maximum
baroreflex-elicited LSNA was significantly reduced in HU rats (204 ± 11.9 vs. 342 ± 30.6% baseline LSNA), as was maximum reflex
gain (
4.0 ± 0.6 vs. 7.8 ± 1.3 %LSNA/mmHg).
Maximum baroreflex-elicited RSNA (259 ± 10.8 vs. 453 ± 28.0%
baseline RSNA), minimum baroreflex-elicited RSNA (2 ± 2.8 vs. 13 ± 4.5% baseline RSNA), and maximum gain (5.8 ± 0.5 vs. 13.6 ± 3.1 %RSNA/mmHg) were significantly decreased in HU rats. Results demonstrate that baroreflex modulation of sympathetic nervous system activity is attenuated after cardiovascular deconditioning in rodents. Data suggest that alterations in the arterial baroreflex may contribute to orthostatic intolerance after a
period of bedrest or spaceflight in humans.
microgravity; hindlimb unweighting; blood pressure; bedrest; orthostatic intolerance
This article has been cited by other articles:
|
|
 |
|
  A. J. Grippo, J. A. Moffitt, and A. K. Johnson Evaluation of Baroreceptor Reflex Function in the Chronic Mild Stress Rodent Model of Depression Psychosom Med, May 1, 2008; 70(4): 435 - 443. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Lin, R. Liu, D. Gozal, W. B. Wead, M. W. Chapleau, R. Wurster, and Z. Cheng Chronic intermittent hypoxia impairs baroreflex control of heart rate but enhances heart rate responses to vagal efferent stimulation in anesthetized mice Am J Physiol Heart Circ Physiol, August 1, 2007; 293(2): H997 - H1006. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Hwang, S. A. Shelkovnikov, and R. E. Purdy Simulated microgravity effects on the rat carotid and femoral arteries: role of contractile protein expression and mechanical properties of the vessel wall J Appl Physiol, April 1, 2007; 102(4): 1595 - 1603. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. J. Mueller, M. J. Sullivan, R. R. Grindstaff, J. T. Cunningham, and E. M. Hasser Regulation of plasma vasopressin and renin activity in conscious hindlimb-unloaded rats Am J Physiol Regulatory Integrative Comp Physiol, July 1, 2006; 291(1): R46 - R52. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. M. Foley, P. J. Mueller, E. M. Hasser, and C. M. Heesch Hindlimb unloading and female gender attenuate baroreflex-mediated sympathoexcitation Am J Physiol Regulatory Integrative Comp Physiol, November 1, 2005; 289(5): R1440 - R1447. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. S. Jung, R. Harrison, K. H. Lee, J. Genut, D. Nyhan, E. M. Brooks-Asplund, A. A. Shoukas, J. M. Hare, and D. E. Berkowitz Simulated microgravity produces attenuated baroreflex-mediated pressor, chronotropic, and inotropic responses in mice Am J Physiol Heart Circ Physiol, August 1, 2005; 289(2): H600 - H607. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. J. Mueller, C. M. Foley, and E. M. Hasser Hindlimb unloading alters nitric oxide and autonomic control of resting arterial pressure in conscious rats Am J Physiol Regulatory Integrative Comp Physiol, July 1, 2005; 289(1): R140 - R147. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. A. Moffitt, A. J. Grippo, and A. K. Johnson Baroreceptor reflex control of heart rate in rats studied by induced and autogenic changes in arterial pressure Am J Physiol Heart Circ Physiol, May 1, 2005; 288(5): H2422 - H2430. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. K. Wilkerson, L. A. Lesniewski, E. M. Golding, R. M. Bryan Jr., A. Amin, E. Wilson, and M. D. Delp Simulated microgravity enhances cerebral artery vasoconstriction and vascular resistance through endothelial nitric oxide mechanism Am J Physiol Heart Circ Physiol, April 1, 2005; 288(4): H1652 - H1661. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. A. Moffitt and A. K. Johnson Short-term fluoxetine treatment enhances baroreflex control of sympathetic nervous system activity after hindlimb unloading Am J Physiol Regulatory Integrative Comp Physiol, March 1, 2004; 286(3): R584 - R590. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Kamiya, D. Michikami, Q. Fu, S. Iwase, J. Hayano, T. Kawada, T. Mano, and K. Sunagawa Pathophysiology of orthostatic hypotension after bed rest: paradoxical sympathetic withdrawal Am J Physiol Heart Circ Physiol, August 7, 2003; 285(3): H1158 - H1167. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. J. Mueller and E. M. Hasser Enhanced sympathoinhibitory response to volume expansion in conscious hindlimb-unloaded rats J Appl Physiol, May 1, 2003; 94(5): 1806 - 1812. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Waki, T. Shimizu, K. Katahira, T. Nagayama, M. Yamasaki, and S.-I. Katsuda Effects of microgravity elicited by parabolic flight on abdominal aortic pressure and heart rate in rats J Appl Physiol, December 1, 2002; 93(6): 1893 - 1899. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. A. Lanfranchi and V. K Somers Arterial baroreflex function and cardiovascular variability: interactions and implications Am J Physiol Regulatory Integrative Comp Physiol, October 1, 2002; 283(4): R815 - R826. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. A. Moffitt, C. M. Heesch, and E. M. Hasser Increased GABAA inhibition of the RVLM after hindlimb unloading in rats Am J Physiol Regulatory Integrative Comp Physiol, September 1, 2002; 283(3): R604 - R614. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. C. Hatton, Q. Yue, J. Chapman, H. Xue, J. Dierickx, C. Roullet, S. Coste, J. B. Roullet, and D. A. McCarron Blood pressure and mesenteric resistance arterial function after spaceflight J Appl Physiol, January 1, 2002; 92(1): 13 - 17. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L.-F. Zhang Vascular adaptation to microgravity: what have we learned? J Appl Physiol, December 1, 2001; 91(6): 2415 - 2430. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. R. Woodman, W. G. Schrage, J. W. E. Rush, C. A. Ray, E. M. Price, E. M. Hasser, and M. H. Laughlin Hindlimb unweighting decreases endothelium-dependent dilation and eNOS expression in soleus not gastrocnemius J Appl Physiol, September 1, 2001; 91(3): 1091 - 1098. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. S. Sangha, S. Han, and R. E. Purdy Simulated microgravity upregulates an endothelial vasoconstrictor prostaglandin J Appl Physiol, August 1, 2001; 91(2): 789 - 796. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. D. Vaziri, Y. Ding, D. S. Sangha, and R. E. Purdy Upregulation of NOS by simulated microgravity, potential cause of orthostatic intolerance J Appl Physiol, July 1, 2000; 89(1): 338 - 344. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. C. Looft-Wilson and C. V. Gisolfi Rat small mesenteric artery function after hindlimb suspension J Appl Physiol, April 1, 2000; 88(4): 1199 - 1206. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Kamiya, S. Iwase, H. Kitazawa, T. Mano, O. L. Vinogradova, and I. B. Kharchenko Baroreflex control of muscle sympathetic nerve activity after 120 days of 6{degrees} head-down bed rest Am J Physiol Regulatory Integrative Comp Physiol, February 1, 2000; 278(2): R445 - R452. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. A. Moffitt, J. C. Schadt, and E. M. Hasser Altered central nervous system processing of baroreceptor input following hindlimb unloading in rats Am J Physiol Heart Circ Physiol, December 1, 1999; 277(6): H2272 - H2279. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. L. Jasperse, C. R. Woodman, E. M. Price, E. M. Hasser, and M. H. Laughlin Hindlimb unweighting decreases ecNOS gene expression and endothelium-dependent dilation in rat soleus feed arteries J Appl Physiol, October 1, 1999; 87(4): 1476 - 1482. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. K. Shoemaker, C. S. Hogeman, and L. I. Sinoway Contributions of MSNA and stroke volume to orthostatic intolerance following bed rest Am J Physiol Regulatory Integrative Comp Physiol, October 1, 1999; 277(4): R1084 - R1090. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. S. Kimmerly and J. K. Shoemaker Hypovolemia and neurovascular control during orthostatic stress Am J Physiol Heart Circ Physiol, February 1, 2002; 282(2): H645 - H655. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
