Signal transduction in pancreatic acinar cell physiology and pathophysiology.

The pancreatic acinar cell is a valuable cell model for understanding how activation of plasma membrane receptors generates signals that propagate, amplify, diversify, and integrate to control cellular function. A primary signaling system involves the activation of heterotrimeric G proteins that stimulate phospholipases, leading to the generation of phospholipid messengers. A major action of the phospholipid messengers is the control of cytoplasmic Ca(2+) levels. The complex mechanisms involved in controlling the initiation, form, and spatial pattern of Ca(2+) release are being revealed in increasing detail and complexity. The connections between the signaling networks and the final events of secretion are beginning to be revealed. Advances have also been made in understanding the processes that underlie the pathologic effects of receptor overactivation.