| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Department of Medicine, University of California, San Diego, La Jolla, CA, USA
* To whom correspondence should be addressed. E-mail: rrichardson{at}ucsd.edu.
To determine the effect of age on quadriceps muscle blood flow (QMBF), leg vascular resistance (LVR), and oxygen uptake (QVO2max), thermal dilution technique was used in conjunction with arterial and venous femoral blood sampling in 6 sedentary young (19.8 ± 1.3yrs) (Y) and 6 sedentary old (66.5 [± 2.1yrs) (O) males during incremental knee extensor exercise (KE). Young and old attained a similar maximal KE work rate (WR)max (Y=25.2 ± 2.1, O=24.1 ± 4 W), and QVO2max (Y=0.52 ± 0.03, O=0.42 ± 0.05 lmin-1). QMBF during KE was reduced in old subjects by ~500ml min-1 across all work rates, with old subjects demonstrating a significantly lower QMBF/W (O=174 ± 20 and Y=239 ± 46 ml min-1watt-1). Although the vasodilatory response to incremental KE was ~142% greater in the old (Y=0.0019 O=0.0046 mmHg min ml-1W-1), consistently elevated leg vascular resistance (LVR) in the old, ~80% higher LVR in the old at WR50% and ~40% higher LVR in the old at WRmax (Y=44.1±3.6, O=31.0 ± 1.7 mmHg min ml-1), dictated that during incremental KE the LVR of the old was never less than that of the young. Pulse pressures, indicative of arterial vessel compliance, were ~36% higher in the old across all work rates. In conclusion, well-matched sedentary young and old subjects with similar quadriceps muscle mass achieved a similar WRmax and QVO2max during incremental KE. The old, despite a reduced QMBF, had a greater vasodilatory response to incremental KE. Given that small muscle mass exercise such as KE utilizes only a fraction of maximal cardiac output, peripheral mechanisms such as consistently elevated leg vascular resistance and greater pulse pressures appear to be responsible for reduced blood flow persisting throughout graded KE in the old.
This article has been cited by other articles:
|
|
 |
|
  D. W. Wray, S. K. Nishiyama, R. A. Harris, and R. S. Richardson Angiotensin II in the Elderly: Impact of Angiotensin II Type 1 Receptor Sensitivity on Peripheral Hemodynamics Hypertension, June 1, 2008; 51(6): 1611 - 1616. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. E. Carlson, B. S. Kirby, W. F. Voyles, and F. A. Dinenno Evidence for impaired skeletal muscle contraction-induced rapid vasodilation in aging humans Am J Physiol Heart Circ Physiol, April 1, 2008; 294(4): H1963 - H1970. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. A. Parker, S. L. Smithmyer, J. A. Pelberg, A. D. Mishkin, and D. N. Proctor Sex-specific influence of aging on exercising leg blood flow J Appl Physiol, March 1, 2008; 104(3): 655 - 664. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. D. Delp, B. J. Behnke, S. A. Spier, G. Wu, and J. M. Muller-Delp Ageing diminishes endothelium-dependent vasodilatation and tetrahydrobiopterin content in rat skeletal muscle arterioles J. Physiol., February 15, 2008; 586(4): 1161 - 1168. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. H. Chung, D. M. Callahan, and J. A. Kent-Braun Age-related resistance to skeletal muscle fatigue is preserved during ischemia J Appl Physiol, November 1, 2007; 103(5): 1628 - 1635. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. W. Wray, S. K. Nishiyama, A. J. Donato, M. Sander, P. D. Wagner, and R. S. Richardson Endothelin-1-mediated vasoconstriction at rest and during dynamic exercise in healthy humans Am J Physiol Heart Circ Physiol, October 1, 2007; 293(4): H2550 - H2556. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. Pinaud, A. Bocquet, O. Dumont, K. Retailleau, C. Baufreton, R. Andriantsitohaina, L. Loufrani, and D. Henrion Paradoxical Role of Angiotensin II Type 2 Receptors in Resistance Arteries of Old Rats Hypertension, July 1, 2007; 50(1): 96 - 102. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. C. Poole and L. F. Ferreira Muscle-energetic and cardio-pulmonary determinants of exercise tolerance in humans: Oxygen exchange in muscle of young and old rats: muscle-vascular-pulmonary coupling Exp Physiol, March 1, 2007; 92(2): 341 - 346. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. J. Donato, L. A. Lesniewski, and M. D. Delp Ageing and exercise training alter adrenergic vasomotor responses of rat skeletal muscle arterioles J. Physiol., February 15, 2007; 579(1): 115 - 125. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. J. Behnke, R. D. Prisby, L. A. Lesniewski, A. J. Donato, H. M. Olin, and M. D. Delp Influence of ageing and physical activity on vascular morphology in rat skeletal muscle J. Physiol., September 1, 2006; 575(2): 617 - 626. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. J. Donato, A. Uberoi, D. W. Wray, S. Nishiyama, L. Lawrenson, and R. S. Richardson Differential effects of aging on limb blood flow in humans Am J Physiol Heart Circ Physiol, January 1, 2006; 290(1): H272 - H278. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. A Dinenno, S. Masuki, and M. J Joyner Impaired modulation of sympathetic {alpha}-adrenergic vasoconstriction in contracting forearm muscle of ageing men J. Physiol., August 15, 2005; 567(1): 311 - 321. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. E. Eklund, K. S. Hageman, D. C. Poole, and T. I. Musch Impact of aging on muscle blood flow in chronic heart failure J Appl Physiol, August 1, 2005; 99(2): 505 - 514. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. S. DeLorey, J. M. Kowalchuk, and D. H. Paterson Adaptation of pulmonary O2 uptake kinetics and muscle deoxygenation at the onset of heavy-intensity exercise in young and older adults J Appl Physiol, May 1, 2005; 98(5): 1697 - 1704. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. N. Proctor, K. U. Le, and S. J. Ridout Age and regional specificity of peak limb vascular conductance in men J Appl Physiol, January 1, 2005; 98(1): 193 - 202. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. E Bearden, G. W Payne, A. Chisty, and S. S Segal Arteriolar network architecture and vasomotor function with ageing in mouse gluteus maximus muscle J. Physiol., December 1, 2004; 561(2): 535 - 545. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. R. Seals and F. A. Dinenno Collateral damage: cardiovascular consequences of chronic sympathetic activation with human aging Am J Physiol Heart Circ Physiol, November 1, 2004; 287(5): H1895 - H1905. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. A. Spier, M. D. Delp, C. J. Meininger, A. J. Donato, M. W. Ramsey, and J. M. Muller-Delp Effects of ageing and exercise training on endothelium-dependent vasodilatation and structure of rat skeletal muscle arterioles J. Physiol., May 1, 2004; 556(3): 947 - 958. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. A. Dinenno Ageing, exercise training, and resistance vessels: more than just no NO? J. Physiol., May 1, 2004; 556(3): 673 - 673. [Full Text] [PDF]
|
|
|
|
|
|
L. Lawrenson, J. Hoff, and R. S. Richardson Aging attenuates vascular and metabolic plasticity but does not limit improvement in muscle VO2 max Am J Physiol Heart Circ Physiol, April 1, 2004; 286(4): H1565 - H1572. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
