Studies of reactivity and distribution of bronchial blood flow in sheep

Two techniques have been used to assess reactivity and distribution of bronchial blood flow in sheep. VDT allows repeated noninvasive measurements of bronchial blood flow without thoracotomy. Bronchial blood flow is highly reactive to pharmacologic agents delivered via right atrium, bronchial artery, or to airways via aerosol. Radiolabeled microspheres allow the assessment of the distribution of this bronchial blood flow within the airways. Airway mucosal/submucosal blood flow appears to receive a disproportionately large fraction of this blood flow, suggesting an active metabolic need. These preliminary studies highlight techniques that should prove useful for further investigations of airway physiology in health and disease.