The health of the oral cavity is maintained by salivary secretions. The principal function of salivary glands is to produce these complex fluids. We utilize in vitro dispersed cells, and cultured cells of salivary glands to understand mechanisms controlling saliva formation. We have focused these studies on autonomic neurotransmitter regulation of secretory events and associated signalling mechanisms. The aging rat parotid gland continues to be employed as a useful model to study autonomic receptor control calcium handling in exocrine acinar cells. During this reporting period the major specific areas of study with these preparations include (1) mechanistic aspects and functional correlates of alpha-adrenoreceptor mobilization of cellular calcium and (2) characterization of neurotransmitter receptor- coupled signalling mechanisms in a cloned rat salivary ductal epithelial cell line.