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 both in vitro and in vivo preparations of rat salivary glands primarily to understand mechanisms controlling saliva formation. We have focused our studies on autonomic neurotransmitter regulation of secretory events in normal, aging and two types of therapy-induced salivary gland dysfunctions (X-radiation, phenothiazines). During the present reporting period specific areas of study were (1) further examination of mechanistic processes in Ca2+ handling by parotid basolateral plasma membrane; (2) determination of the presence, and importance, of a Na+, K+, 2 Cl transport mechanism in parotid fluid secretion; (3) the possible regulatory role of VIP (vasoactive intestinal polypeptide) in parotid secretion; (4) the evauation of chlorpromazine as a competitive muscarinic antagonist; and (5) the development and characterization of an epithelial cell line from rat submandibular glands.