Effects of atropine or high frequency burst excitation on the composition of parasympathetic rat parotid saliva.

In the presence of atropine continuous trains of impulses applied to the auriculo-temporal nerve at relatively high frequencies evoked a flow of parotid saliva that amounted to 5-10% of that before administration of the muscarinic blocker. The output of total protein, amylase, sodium and potassium decreased markedly. However, in terms of concentration protein and amylase increased, while sodium decreased and potassium was unchanged. When, in the absence of atropine, the continuous mode of stimulation was replaced by bursts of impulses of high frequencies the amount of saliva decreased. However, the concentration of protein, amylase and potassium increased, while the concentration of sodium decreased. The findings are discussed in relation to a possible peptidergic innervation of the secretory elements.