EPINEPHRINE PROMOTES GROWTH AND DIFFERENTIATION OF HUMAN TRACHEAL GLAND-CELLS IN CULTURE

Submucosal gland cells isolated from human tracheas by enzymatic digestion and cultured in the absence or presence of epinephrine (E) were used to investigate the possible action of this catecholamine on the physiology of the gland secretory cells issued from the human trachea. A 3 x 10(-6) M concentration of E shortens the doubling time of growth and increases the cells' confluency rate. On the other hand, E appears to induce cell polarity in terms of differential secretion apically versus basolaterally. Furthermore, when human tracheal gland cells are cultured in the presence of E, a maximal cell stimulability by different agonists occurs from 8 days after confluency and then remains identical for 10 days, allowing us to compare the action of different adrenergic and cholinergic agonists on the proteinase bronchial inhibitor and the radiolabeled glycoconjugate secretion. As previously described, secretions of bronchial inhibitor and high molecular weight glycoconjugates were stimulated both by alpha- and beta-adrenergic and by cholinergic agonists but at a much higher rate when cells were cultured in the presence of E. These results indicate that E improves cultured human tracheal glandular cell growth and differentiation in that it increases their polarity and their ability to respond to adrenergic and cholinergic agonists.