title: Goblet cell degranulation in isolated canine tracheal epithelium: response to exogenous ATP, ADP, and adenosine.
abstract: Mucin secretion by goblet cells was determined by quantifying degranulation events (DE) in isolated, superficial epithelium from canine trachea. The epithelium was isolated and explanted to a novel transparent, permeable support, and the goblet cells were visualized by video microscopy. Baseline degranulation events were quantified at 0.05 DE/min. Luminal ATP (10(-4) M, n = 10) stimulated a biphasic secretory response; a burst, maximum rate = 87.9 +/- 25.3, was followed by a plateau, rate = 1.9 +/- 0.3 DE/min. Serosal ATP elicited a complex set of responses: 9 cells failed to respond, 13 exhibited a trivial response, and 31 responded vigorously but with highly variable patterns of degranulation. Nonhydrolyzable 5'-adenylylimidodiphosphate caused degranulation from both sides of the epithelium. Luminal ADP and adenosine were ineffective. Serosal ADP and adenosine elicited a range of responses that was similar in diversity and magnitude to the ATP response. Our conclusions were as follows: 1) goblet cells in the superficial epithelium of the airway can be studied at the single-cell level in explants; 2) nucleotides stimulate goblet cells to secrete mucin; and 3) the goblet cell expresses different nucleotide receptors on its apical and basolateral membranes.
authors.affiliation: Department of Physiology, University of North Carolina, Chapel Hill 27599.
authors.forename: C W
authors.initials: CW
authors.lastname: Davis
authors.forename: M L
authors.initials: ML
authors.lastname: Dowell
authors.forename: M
authors.initials: M
authors.lastname: Lethem
authors.forename: M
authors.initials: M
authors.lastname: Van Scott
mesh_terms: D000227:Adenine Nucleotides / Q000494:pharmacology; D000241:Adenosine / Q000494:pharmacology*; D000244:Adenosine Diphosphate / Q000494:pharmacology*; D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000818:Animals; D015550:Cell Degranulation / Q000187:drug effects*; D003101:Collodion; D046508:Culture Techniques; D004285:Dogs; D004847:Epithelial Cells; D004848:Epithelium / Q000378:metabolism; D008297:Male; D011983:Receptors, Purinergic / Q000378:metabolism; D014132:Trachea / Q000166:cytology* / Q000378:metabolism
chemical_list: D000227:Adenine Nucleotides; D011983:Receptors, Purinergic; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D003101:Collodion; D000241:Adenosine