Increasing lung volume improves upper airway airflow dynamics via passive mechanisms such as reducing upper airway extraluminal tissue pressures (ETP) and increasing longitudinal tension via tracheal displacement. We hypothesized a threshold lung volume for optimal mechanical effects on upper airway airflow dynamics. Seven supine, anesthetized, spontaneously breathing New Zealand White rabbits ...

We postulated that prolonged exposure to intermittent positive-pressure ventilation (IPPV) with high pressure (HIPPV) alone without hyperoxia promotes the development of airway hyperresponsiveness and remodeling. To test this hypothesis, young rats were ventilated under halothane anesthesia with HIPPV (maximum inspiratory pressure at 32-35 cmH2O in 70% nitrous oxide and 30% O2) for 3.5-4 h dail...

BACKGROUND The airway functions are profoundly affected in many diseases including asthma, chronic obstructive pulmonary disease (COPD) and cystic fibrosis (CF). CF the most common lethal autosomal recessive genetic disease is caused by mutations of the CFTR gene, which normally encodes a multifunctional and integral membrane protein, the CF transmembrane conductance regulator (CFTR) expressed ...

Hypocapnia constricts peripheral airways in vivo. This study investigated the role of airway smooth muscle in this phenomenon and the mechanism of hypocapnia-induced contraction in vitro. Isometric tension, intracellular pH (pHi) and intracellular free calcium concentration ([Ca2+]i) were measured in porcine airway smooth muscles suspended in organ baths in the presence of 5% or 0% CO2. In trac...

Airway epithelium releases inhibitory factors, such as nitric oxide (NO) and prostaglandin E2 (PGE2), which may counteract bronchoconstriction. We investigated whether epithelium-derived inhibitory substances exert a crucial influence on bovine tracheal responsiveness in vitro. Isotonic and isometric contractions in response to histamine of intact and epithelium-denuded tracheal smooth muscle s...