Defective beta-adrenergic secretory responses in submandibular acinar cells from cystic fibrosis patients.

The in-vitro investigation of secretory responses of submandibular tissues from three cystic fibrosis (CF) patients and four control subjects showed that responses to a beta-adrenergic stimulus (isoproterenol) were much poorer in CF cells than in control cells. The beta-adrenergic secretory responses of the CF cells (as measured by amylase and mucin secretion) were increased in the presence of 3-isobutyl-l-methyl xanthine, a cyclic nucleotide phosphodiesterase inhibitor. Perhaps an alteration in a regulator of cyclic adenosine monophosphate and Ca2+ metabolism in CF cells is responsible for the decrease in beta-adrenergic function. This proposal would account for the defective regulation of protein secretion, Cl- transport, and Ca2+ homoeostasis in CF exocrine cells and thus might be directly related to the genetic defect.