TY - JOUR
T1 - Lack of involvement of the autonomic nervous system in early ventilatory and pulmonary vascular acclimatization to hypoxia in humans
AU - Liu, C
AU - Smith, TG
AU - Balanos, George
AU - Brooks, J
AU - Crosby, A
AU - Herigstad, M
AU - Dorrington, KL
AU - Robbins, PA
PY - 2007/2/1
Y1 - 2007/2/1
N2 - The activity within the autonomic nervous system may be altered following sustained exposure to hypoxia, and it is possible that this increase in activity underlies the early acclimatization of both ventilation and the pulmonary vasculature to hypoxia. To test this hypothesis, seven individuals were infused with the ganglionic blocker trimetaphan before and after an 8 h exposure to hypoxia. The short half-life of trimetaphan should ensure that the initial infusion does not affect acclimatization to the 8 h hypoxia exposure, and the use of a ganglion blocking agent should inhibit activity within all branches of the autonomic nervous system. During the infusions of trimetaphan, measurements of ventilation and echocardiographic assessments of pulmonary vascular tone (DeltaPmax) were made during euoxia and during a short period of isocapnic hypoxia. Subjects were also studied on two control days, when a saline infusion was substituted for trimetaphan. Trimetaphan had no effect on either euoxic ventilation or the sensitivity of ventilation to acute hypoxia. Trimetaphan significantly reduced DeltaPmax in euoxia (P
AB - The activity within the autonomic nervous system may be altered following sustained exposure to hypoxia, and it is possible that this increase in activity underlies the early acclimatization of both ventilation and the pulmonary vasculature to hypoxia. To test this hypothesis, seven individuals were infused with the ganglionic blocker trimetaphan before and after an 8 h exposure to hypoxia. The short half-life of trimetaphan should ensure that the initial infusion does not affect acclimatization to the 8 h hypoxia exposure, and the use of a ganglion blocking agent should inhibit activity within all branches of the autonomic nervous system. During the infusions of trimetaphan, measurements of ventilation and echocardiographic assessments of pulmonary vascular tone (DeltaPmax) were made during euoxia and during a short period of isocapnic hypoxia. Subjects were also studied on two control days, when a saline infusion was substituted for trimetaphan. Trimetaphan had no effect on either euoxic ventilation or the sensitivity of ventilation to acute hypoxia. Trimetaphan significantly reduced DeltaPmax in euoxia (P
U2 - 10.1113/jphysiol.2006.118190
DO - 10.1113/jphysiol.2006.118190
M3 - Article
C2 - 17138611
SN - 1469-7793
VL - 579
SP - 215
EP - 225
JO - The Journal of Physiology
JF - The Journal of Physiology
ER -