| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Department of Science Applied to Biological Systems, University of Cagliari, cagliari, Italy; Department of Biological Science, University of Torino, torino, Italy
2 Department of Science Applied to Biological Systems, University of Cagliari, cagliari, Italy
3 Department of Science Applied to Biological Systems, University of Cagliari, Cagliari, Italy
4 Department of Biological Science, University of Torino, Torino, Italy
5 Human Physiology, University of Cagliari, Cagliari, Italy
* To whom correspondence should be addressed. E-mail: crisafulli{at}tiscali.it.
Accumulation of metabolic end-products within skeletal muscle stimulates sensory nerves, thus evoking a pressor response termed metaboreflex. The aim of this study was to evaluate changes in hemodynamics occurring during metaboreflex activation obtained by post-exercise muscle ischemia (PEMI) after two different exercise intensities. In twelve healthy subjects the metaboreflex was studied with the PEMI method at the start of recovery from one leg dynamic knee extension performed at intensities of 30% (PEMI 30%) and 70% (PEMI 70%) of the maximum workload achieved in a preliminary test. Control exercise recovery tests at the same intensities were also conducted. Central hemodynamics was evaluated by means of impedance cardiography. The main findings were that during metaboreflex: 1) exercise conducted against the higher workload caused a more pronounced blood pressure increase than the strain conducted against the lower workload; 2) during PEMI 70% this blood pressure response was mainly achieved through enhancement of myocardial contractility which increased stroke volume and, in turn, cardiac output, whereas during PEMI 30% the blood pressure response was reached predominantly by means of vasoconstriction. Thus, a substantial enhancement of myocardial contractility was reached only in the PEMI 70% test. These results suggest that hemodynamic regulation during metaboreflex engagement caused by PEMI in humans is dependent on the intensity of the previous effort. Moreover, the cardiovascular response during metaboreflex is not merely achieved by vasoconstriction alone, but it appears that there is a complex interplay between peripheral vasoconstriction and heart contractility recruitment.
This article has been cited by other articles:
|
|
 |
|
  A. Crisafulli, R. Milia, A. Lobina, M. Caddeo, F. Tocco, A. Concu, and F. Melis Haemodynamic effect of metaboreflex activation in men after running above and below the velocity of the anaerobic threshold Exp Physiol, April 1, 2008; 93(4): 447 - 457. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Ichinose, J. A. Sala-Mercado, D. S. O'Leary, R. L. Hammond, M. Coutsos, T. Ichinose, M. Pallante, and F. Iellamo Spontaneous baroreflex control of cardiac output during dynamic exercise, muscle metaboreflex activation, and heart failure Am J Physiol Heart Circ Physiol, March 1, 2008; 294(3): H1310 - H1316. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. K. Shoemaker, L. Mattar, P. Kerbeci, S. Trotter, P. Arbeille, and R. L. Hughson WISE 2005: stroke volume changes contribute to the pressor response during ischemic handgrip exercise in women J Appl Physiol, July 1, 2007; 103(1): 228 - 233. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Crisafulli, E. Salis, F. Tocco, F. Melis, R. Milia, G. Pittau, M. A. Caria, R. Solinas, L. Meloni, P. Pagliaro, et al. Impaired central hemodynamic response and exaggerated vasoconstriction during muscle metaboreflex activation in heart failure patients Am J Physiol Heart Circ Physiol, June 1, 2007; 292(6): H2988 - H2996. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
