With the cloning of complementary DNAs encoding the receptors for the most physiologically important pancreatic secretagogues, the past year has provided resources key in understanding the proximal steps in stimulus-secretion coupling in the acinar cell. In addition, new acinar cell agonists have been identified, the importance of neural regulation of acinar cell function has been appreciated, the regulatory roles of serine-threonine and tyrosine protein phosphorylation have been expanded, and the description of numerous small guanine nucleotide—binding proteins in various compartments of the acinar cell has begun. In addition to these biochemical and physiologic advances, sensitive methodologies to define the spatial and temporal events that occur in the cell have been established. These findings should contribute to better understanding the molecular basis of signal transduction and integration of responses in polarized secretory epithelia.