Pulmonary vascular resistance distribution and recruitment of microvascular surface area
| Autor: | N. A. Pou, R. E. Parker, N. A. Lomangino, K. A. Overholser, Thomas R. Harris |
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| Rok vydání: | 1994 |
| Předmět: |
Hemodynamic resistance
Viscosity Physiology Capillary action Chemistry Blood Pressure In Vitro Techniques Capillaries Capillary Permeability medicine.anatomical_structure Perfusion rate Propylene Glycols Vasoconstriction Physiology (medical) Extravascular Lung Water Vascular resistance medicine Biophysics Animals Vascular Resistance Capillary surface Rabbits Hypoxia Lung |
| Zdroj: | Journal of Applied Physiology. 77:845-855 |
| ISSN: | 1522-1601 8750-7587 |
| DOI: | 10.1152/jappl.1994.77.2.845 |
| Popis: | To test the hypothesis that the distribution of hemodynamic resistance is involved in the control of pulmonary capillary surface area, we measured permeability-surface area product (PS) and longitudinal resistance distribution (LRD) as functions of perfusion rate in isolated rabbit lungs under zone II conditions (n = 10) and through the zone II-III transition (n = 4). PS, considered to be indicative of functioning capillary surface area, was measured with the aid of the diffusion-limited tracer [14C]propanediol, whereas LRD was determined using a viscous bolus technique. LRD was seen to change character with increasing flow and increasing PS/surface area, becoming bimodal with low central resistance as full capillary recruitment was approached in zone III. Effects of hypoxic ventilation were studied in zone II in five lungs; it was found that hypoxia altered the LRD and eradicated the normoxic dependence of PS/surface area on perfusion rate. It was concluded that LRD is involved in the determination of functioning capillary surface area. |
| Databáze: | OpenAIRE |
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