Browsing by Author "Del Río, R"

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    Cardiovascular and ventilatory acclimatization induced by chronic intermittent hypoxia
    (2005) Iturriaga, R; Rey, S; Del Río, R
    Patients with obstructive sleep apnea (OSA) show augmentes ventilatory, sympathetic and cardiovascular responses to hypoxia. The facilitatory effect of chronic intermittent hypoxia (CIH) on the hypoxic ventilatory response has been attributed to a potentiation of the carotid body (CB) chemosensory response to hypoxia. However. it is a matter of debate whether the effects induced by CIH oil ventilatory responses to hypoxia are due to all enhanced CB activity. Recently, we studied the effects of short cyclic hypoxic episodes oil cat cardiorespiratory reflexes, heart rate variability, and CB chemosensory activity. Cats were exposed to cyclic hypoxic episodes repealed during 8 hours for 4 days. Our results showed that CIH selcectively enhanced ventilatory and carotid chemosensory responses to acute hypoxia. Exposure to CIH did not increase basal arterial pressure, heart-rate. or-the changes induced by acute hypoxia. However. the spectral analysis of heart rate variability of CIH cats showed a marked increase of the low/high frequency ratio and an increased variability in the low frequency band of heart rate variability, similar to what is observed ill OSA patients. Thus, it is likely that the enhanced CB reactivity to hypoxia may contribute to the augmented ventilatory response to hypoxia.