Calcium and cGMP in isolated rat parotid acinar cells

The role of calcium ions in the activation of guanylate cyclase and in the propagation of the effects of cGMP during activation of the muscarinic cholinergic receptors was studied in isolated rat parotid acinar cells. It was demonstrated that the requirement for extracellular calcium is complete in the transduction of information from the muscarinic receptor to the guanylate cyclase, and partial in the steps beyond the synthesis of cGMP.