This study assessed the hemodynamic and permeability effects of exogenous, synthetic leukotriene B4 (LTB4) on normal rat lungs and lungs from rats preexposed to oxygen for 48 h, which were isolated and perfused at constant flow in vitro. Adult, Sprague-Dawley rats were exposed to air or >97% O2 for 48 h. After exposure, their lungs were removed from the thorax, ventilated with normoxic gas, and perfused at 12 ml/min with Krebs-Ringer bicarbonate buffer which contained 5 mM glucose and 3 mg/ml albumin. A total of 5.55 μg of synthetic LTB4 was infused in three separate boluses over 15 minutes. Perfusion and airway pressures were monitored, and the lungs release of 6-ketoprostaglandin F1α and thromboxane B2 (TXB2) into the effluent from the pulmonary vasculature was measured by radioimmunoassay. The LTB4 had no measurable effects on pulmonary vascular pressures. LTB4 infusion caused a pronounced increase in permeability, indicated by increased albumin concentrations in alveolar lavage fluid from O2-preexposed lungs. Release of TXB2 from both air- and O2-preexposed lungs was increased after LTB4 infusion, while the change in 6-ketoprostaglandin F1α release was not statistically significant. Both the increase in permeability enhanced TXB2 released after LTB4 infusion were inhibited by 10 μM indomethacin in the perfusate. These data indicate that exogenous LTB4 increases microvascular permeability in O2-exposed lungs in association with increased release of TXB2 into the pulmonary vascular effluent.
|Original language||English (US)|
|Number of pages||8|
|Journal||Prostaglandins Leukotrienes and Essential Fatty Acids|
|State||Published - Jan 1 1988|
ASJC Scopus subject areas
- Clinical Biochemistry
- Cell Biology