INTRACELLULAR FREE CA2-FIBROSIS HUMAN TRACHEAL GLAND-CELLS( DYNAMIC CHANGES TO HISTAMINE ARE REDUCED IN CYSTIC)

This study documents a difference between cystic fibrosis human (CF-HT G) and normal human (HTG) tracheal gland cells: the ability of histami ne to induce an increase of intracellular free calcium concentration [ Ca2+](i) was abnormally reduced in CF-HTG cells. The magnitude of the [Ca2+](i) peak rise in response to histamine is smaller in CF-HTG cell s than in HTG cells, and the percentage of CF-HTG cells that increase [Ca2+](i) is decreased compared with HTG cells, In contrast to histami ne, the human neutrophil elastase (HNE) stimulation of both CF-HTG and HTG cells generated [Ca2+](i) asynchronous oscillations and the magni tude of the peak [Ca2+](i) response as well as the percentage of respo nding cells were similar for both groups. By videomicroscopy observati ons, the secretory response (exocytosis of secretion granules) of CF-H TG cells occurred with HNE, but not with histamine, thus suggesting th at [Ca2+](i) asynchronous oscillations may be linked to the exocytosis process in human tracheal gland cells.