New approaches for determining the site of salivary fluid secretory disorders

Considerable progress has been made in understanding the events which underlie salivary fluid secretion. We have utilized novel approaches to evaluate the functional status of three distinct sites in the secretory cascade. First, salivary sympathetic nerve function studies used isotopic dopamine to measure catecholamine uptake and metabolism in vivo. Second, salivary muscarinic-cholinergic receptors were characterized in vivo by use of stereo-specific ligands and pharmacokinetic analyses. Finally, microfluorometric methods were used to study intracellular Ca2+ signaling in dispersed cells prepared from biopsied tissue. We conclude that it is possible to determine the functional status of key steps in salivary fluid generation with isotopic and fluorometric imaging techniques.