Philippe Haouzi

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The purpose of this study was to examine the influence of the type of exercise (running vs. cycling) on the O2 uptake V(O2) slow component. Ten triathletes performed exhaustive exercise on a treadmill and on a cycloergometer at a work rate corresponding to 90% of maximal VO2 (90% work rate maximal V(O2)). The duration of the tests before exhaustion was(More)
This review examines the evidence that skeletal muscles can sense the status of the peripheral vascular network through group III and IV muscle afferent fibers. The anatomic and neurophysiological basis for such a mechanism is the following: 1) a significant portion of group III and IV afferent fibers have been found in the vicinity and the adventitia of(More)
The aim of this study was to identify some of the mechanisms that could be involved in blunted ventilatory response (VE) to exercise in the supine (S) position. The contribution of the recruitment of different muscle groups, the activity of the cardiac mechanoreceptors, the level of arterial baroreceptor stimulation, and the hemodynamic effects of gravity(More)
RATIONALE We have recently reported that infusion of a solution containing methemoglobin (MetHb) during exposure to hydrogen sulfide results in a rapid and large decrease in the concentration of the pool of soluble/diffusible H2S in the blood. However, since the pool of dissolved H2S disappears very quickly after H2S exposure, it is unclear if the ability(More)
Acute H(2)S intoxication produces an increase in ventilation followed by a fatal central apnea. The sites of mediation of H(2)S induced hyperpnea and apnea have been investigated since the early 20th century in various animal models. Hyperpnea is mediated by the arterial chemoreceptors, an effect that can be reproduced by injecting a solution of H(2)S at(More)
It has long been recognized that at the onset of a dynamic muscular exercise the ventilatory and the circulatory (blood flow) responses appear to be matched, thereby maintaining arterial blood gas homeostasis. Such a coupling has recently been suggested to rely upon ventilatory reflex triggered by mechanoreceptors encoding changes in muscle blood flow or,(More)
For over a century of creative research, many theories on the possible mechanisms controlling respiration during exercise have been developed and discussed. One of the most enduring questions is certainly related to the mechanisms that can prevent P(a)(CO(2)) rising when CO(2) production increases. As multiple systems and structures are capable of(More)
During exercise by healthy mammals, alveolar ventilation and alveolar-capillary diffusion increase in proportion to the increase in metabolic rate to prevent PaCO2 from increasing and PaO2 from decreasing. There is no known mechanism capable of directly sensing the rate of gas exchange in the muscles or the lungs; thus, for over a century there has been(More)
This study was designed to test the hypothesis that the frequency response of the systems controlling the motor activity of breathing and walking in quadrupeds is compatible with the idea that supra-spinal locomotor centres could proportionally drive locomotion and ventilation. The locomotor and the breath-by-breath ventilatory and gas exchange (CO2 output(More)
It has recently been proposed that afferent fibers from skeletal muscle could sense the state of the microvascular circulation, linking ventilation to the degree of peripheral perfusion or vascular distension (Huszczuk et al., Respir. Physiol., 91:207-226, 1993). Ventilatory and circulatory responses to manipulation of peripheral vascular pressures in the(More)