Salivary secretions: narcolepsy and central nervous system stimulants

In an ongoing attempt to develop a model to study the influence of various diseases and drugs on saliva, we studied persons with narcolepsy treated with central nervous system stimulants. The aim was to study the secretion of salivary proteins in narcolepsy in the presence and absence of central nervous system stimulants. For this purpose, two proteins synthesized in acinar cells, acidic proline-rich proteins (PRPs) and statherin, were selected. Persons with narcolepsy treated with central nervous system stimulants only were included, n = 12, ages 14 to 68, seven females. Citric-acid-stimulated parotid and submandibular/sublingual saliva samples were collected from these persons during medication, after a drug-free period of one week, at least two weeks after the drug had been re-introduced, and from a matched healthy control group. PRP and statherin concentrations were determined by means of reversed-phase and anion exchange chromatography, respectively. Both concentration and output of statherins and PRPs were increased in persons with narcolepsy receiving central nervous system stimulants compared with healthy control individuals. When the drug was withdrawn, salivary flow rates were not influenced. In contrast, withdrawal of the drug led to a significantly decreased secretion of PRPs and statherin. The reduced protein secretion may reflect decreased adrenergic activation in narcolepsy, to be reversed by treatment with central nervous system stimulants. It can be concluded that measurements of both salivary fluid and salivary proteins may be necessary for an overall evaluation of the effects of a given drug or disease on salivary secretion.