Effects of Perfluoroisobutene on Guinea Pig Isolated Lung Preparations.
CHEMICAL AND BIOLOGICAL DEFENCE ESTABLISHMENT PORTON DOWN (UNITED KINGDOM)
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Effects of perfluoroisobuteno PFIB on lung pharmacology were investigated using three preparations The isolated, ventilated, perfused lung IVPL, the tracheally-perfused lung TPL and the tracheal strip TS. The IVPL taken from PFIB exposed animals showed decreased tidal volume TV and compliance Cdyn, and increased lung resistance LR, but no PFIB-induced chemical mediator release was detected by bioassay. in vitro inhalation exposure of the IVPL to PFIB caused a dose-related, reversible bronchoconstriction increased LR, decreased TV and Cdyn within 1-5 minutes no mediator release was detected by bioassay. A greatly diminished bronchoconstriction occurred following a second exposure to PFIB, suggesting that PFIB may stimulate the release of an exhaustible mediator that produces bronchoconstriction but does not produce a response in the bioassay tissues. The mediator may initiate responses which lead to pulmonary oedema. The TPL removed from PFIB-exposed guinea pigs showed increased sensitivity to 5-hydroxytryptamine, bradykinin, isoprenaline and a thromboxane A2 analogue, but not to carbachol, histamine, prostaglandin D2, adenosine or potassium. These changes were not detected in the TS. If PFIB-induced changes in lung pharmacology contribute to oedema, antagonists of identified mediators may be useful as pretreatmentstherapies to pulmonary oedemagens.
- Medicine and Medical Research