We examined the effect of platelet-activating factor (PAF) on beta-adrenoceptors in the membranes of human lung and the functional responses to methacholine, histamine and isoproterenol in human lung parenchyma and tracheal strips. Preincubation of the human lung slices with 0.1 uM PAF decreased the density of beta-adrenoceptors without a change in the affinity. In the functional studies, a subthreshold dose of PAF (0.1 uM) significantly reduced the potency of isoproterenol to reverse methacholine or histamine-induced contraction. BN 52021, a PAF antagonist, protected against these PAF-induced changes. These findings suggest that PAF-induced down-regulation of beta-adrenoceptors could be a mechanism of the non-specific airway hyperreactivity in asthma.
|Number of pages||6|
|Journal||Biochemical and Biophysical Research Communications|
|Publication status||Published - Feb 27 1987|
All Science Journal Classification (ASJC) codes
- Molecular Biology