Conventional wisdom suggests that the events occuring during specific antigen challenge are the most critical for understanding bronchial asthma, however, we have evidence that suggests that long before antigen challenge the exposure of some cells to specific reaginic antibodies alters the membrane of these cells. The long term objectives of the applicants' laboratory is to clarify the relationship between specific reaginic antibodies and airway smooth muscle cells and clarify the relationship between other """"""""asthmatic disorder"""""""" related agents such as chemotactic factor (FMLP) and complement fragment (C5a) and airway smooth muscle cells. Specifically, this application will attempt to identify whether sensitization-induced changes of airway smooth muscle cell membrane can occur in the absence of other cells. For this purpose, we will use a technique of primary tissue culture of airway smooth muscle cells. These cells will be exposed to highly purified, antigen specific reaginic antibodies, and will be evaluated by electrophysiological and contractile characteristics using glass microelectrode technology and sequential photography, respectively. Our recent experiments suggest that sensitization leads to the activation of the protein kinase C. Therefore, we will investigate the early events of membrane pertubation as measured by phosphatidyl inositol breakdown. By using specific markers for hydrogen, calcium and sodium and spectroflurometry, we will analyze kinetics of the intracellular changes in sodium, calcium and cytoplasmatic pH. These studies will establish similarities and differences between activation of cells induced by sensitization, compared to other models of cell activation. This proposal offers fundamentally new concepts pertinent to understanding he mechanisms of bronchial asthma. We believe that the results of this proposal could lead to a more rational therapy for this disease.
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