ATP AND UTP INCREASE SECRETION OF BRONCHIAL INHIBITOR BY HUMAN TRACHEAL GLAND-CELLS IN CULTURE

The effects of ATP and UTP on intracellular Ca2+ levels and on the sec retion of the bronchial inhibitor and high-molecular-weight glycoprote ins were studied in cultures of human bronchotracheal gland cells. ATP , adenosine 5'-O-(3-thiotriphosphate) (ATP-gammaS), and UTP increased intracellular Ca2+ levels in a manner that was partially dependent on the presence of extracellular Ca2+. Other nucleotides (ADP, alpha,beta -methylene ATP, beta,gamma-methylene ATP, and 2-methyl-thio ATP) and a denosine were ineffective, thus suggesting the presence of a ''nucleot ide'' receptor specific for ATP and UTP. At concentrations similar to those that raised intracellular Ca2+ concentration, ATP, UTP, and ATPg ammaS stimulate the secretion of the bronchial inhibitor. ATP and UTP also increase the production of sulfated high-molecular-weight glycopr oteins. These results indicate the presence in human tracheal gland ce lls of a nucleotide receptor that mediates intracellular Ca2+ mobiliza tion and controls the secretion of macromolecules.