Time-dependent ventilatory responses to episodic and continuous isocapnic hypoxia were measured in unidirectionally ventilated, awake ducks. Three protocols were used: (1) ten 3-min episodes of moderate hypoxia (10% O(2)) with 5-min normoxic intervals; (2) three 3-min episodes of severe hypoxia (8% O(2)) with 5-min normoxic intervals; and (3) 30-min of continuous moderate hypoxia. Ventilation (V(I)) increased immediately within a hypoxic episode (acute response), followed by a further slow rise in V(I) (short-term potentiation). The peak V(T) response increased from the first to second moderate hypoxic episode (progressive augmentation), but was unchanged thereafter. During normoxic intervals, V(I) increased progressively (56% following the tenth episode; long term facilitation). Time-dependent changes were not observed during or following 30-min of continuous hypoxia. Although several time-dependent ventilatory responses to episodic hypoxia are observed in awake ducks, they are relatively small and biased towards facilitation versus inhibitory mechanisms.
CITATION STYLE
Powell, F. L., Mitchell, G. S., Hopkins, S. R., & Milsom, W. K. (2001). Time domains of the hypoxic ventilatory response. Respiration Physiology, 124(2), 117–28. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/11164203
Mendeley helps you to discover research relevant for your work.