Prostaglandins (PGs) have been shown to play modulating roles in regulating secretory activities during direct stimulation of both branches of the autonomic innervations to rat salivary glands. The modulating role of exogenous PGs in regulating acetylcholine release during parasympathetic nerve stimulation to rat salivary glands will be further studied. Direct effects of PGs and their modulating effects on agonist-induced net flux of 45Ca of rat parotid acinar cells also will be examined. PGE2 was released into nerve-evoked saliva during autonomic nerve stimulation. The origin and significance of this release is not clear. Biosynthesis and release of PGE2 as well as PGF2delta during autonomic stimulation (nerve and agonist stimulation) will be further investigated. Biosynthetic capacities of rat salivary glands for PGs will be studied in the short term culture of rat submandibular gland acini. Levels of PGE2 of submandibular glands of reserpine-treated rats were higher than those of controls. To determine if the increase in glandular PGE2 levels is found only with reserpine or is a general finding with any manipulations leading to norepinephrine depletion, effects of surgical denervation and 6-hydroxydopamine treatment on PGE2 content of salivary glands will be examined. To see whether the increased PGE2 due to reserpine can be released into nerve-evoked saliva, parasympathetic stimulation of rat salivary glands of reserpine-treated rats will be made. This may be of some value for diagnosis of cystic fibrosis since the chronically-reserpine treated rat is used as an animal model for this disease. These studies would provide a better understanding of modulating roles of PGs in regulating autonomic activities of salivary glands.