TY - JOUR
T1 - Flow-induced vasodilation in the ferret lung
AU - Chammas, Joseph H.
AU - Rickaby, David A.
AU - Guarin, Margarita
AU - Linehan, John H.
AU - Hanger, Christopher C.
AU - Dawson, Christopher A.
PY - 1997/8
Y1 - 1997/8
N2 - To examine the possibility that shear stress may be a pulmonary vasodilator stimulus, we studied the effect of changing blood flew on the diameters of small pulmonary arteries in isolated perfused ferret lung lobes. The arteries studied were in the ~0.3-to 1.3-mm-diameter range, and the diameters were measured by using microfocal X-ray imaging. The diameters were measured at two flow rates, 10 and 40 ml/min, with the intravascular pressure in the measured vessels the same at the two flow rates as the result of venous pressure adjustment. The response to a change in flow was studied under both normoxic and hypoxic conditions. Hypoxia was used to elevate pulmonary arterial tone to increase the likelihood of detecting a vasodilator response. Under normoxic conditions, changing flow had little effect on the arterial diameters, but under hypoxic conditions the arteries were consistently larger at the higher flow than at the lower flow, even though the distending pressure was the same at the two flow rates. The results are consistent with the hypothesis that shear stress is a pulmonary vasodilator stimulus.
AB - To examine the possibility that shear stress may be a pulmonary vasodilator stimulus, we studied the effect of changing blood flew on the diameters of small pulmonary arteries in isolated perfused ferret lung lobes. The arteries studied were in the ~0.3-to 1.3-mm-diameter range, and the diameters were measured by using microfocal X-ray imaging. The diameters were measured at two flow rates, 10 and 40 ml/min, with the intravascular pressure in the measured vessels the same at the two flow rates as the result of venous pressure adjustment. The response to a change in flow was studied under both normoxic and hypoxic conditions. Hypoxia was used to elevate pulmonary arterial tone to increase the likelihood of detecting a vasodilator response. Under normoxic conditions, changing flow had little effect on the arterial diameters, but under hypoxic conditions the arteries were consistently larger at the higher flow than at the lower flow, even though the distending pressure was the same at the two flow rates. The results are consistent with the hypothesis that shear stress is a pulmonary vasodilator stimulus.
KW - Hypoxic pulmonary vasoconstriction
KW - Nitric oxide
KW - Pulmonary arterial diameters
KW - Shear stress
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U2 - 10.1152/jappl.1997.83.2.495
DO - 10.1152/jappl.1997.83.2.495
M3 - Article
C2 - 9262445
AN - SCOPUS:0030861263
VL - 83
SP - 495
EP - 502
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
SN - 8750-7587
IS - 2
ER -