Neural control of salivary myoepithelial cells.

1. The pressures in the ducts of the submaxillary, parotid and sublingual glands were recorded in cats under chloralose anaesthesia. A single stimulus applied to the parasympathetic glandular nerve caused a pressure rise, the size of which increased with the initial pressure. This response was abolished by a small dose of atropine.2. The effect was not due to salivary secretion, since the single stimulus caused salivation only exceptionally. Repetitive stimulation at frequencies too low to evoke secretion could produce summated pressure responses.3. The single stimulus applied to the chorda tympani was found to cause vasodilatation in the submaxillary gland. This was abolished by a small dose of atropine, together with the pressure rise in the duct. However, repetitive stimulation still caused marked vasodilatation but no pressure response. It was therefore inferred that the pressure rise obtained before atropine was not due to vasodilatation in the gland.4. It is concluded that the myoepithelial cells of the salivary glands are supplied with a parasympathetic motor innervation which can cause them to contract.5. Sympathetic stimulation caused no pressure rise when a single stimulus was given but only when repetitive stimulation was used at a frequency approaching that required for secretion.