Dependence of functional vasodilatation in the cat submaxillary gland upon stimulation frequency

1. Submaxillary gland blood flow and salivation have been measured in anaesthetized cats and the chorda-lingual nerve has been stimulated at different frequencies. 2. At low stimulation frequencies (1–5 Hz) there was a large transient increase in blood flow followed by a more modest maintained increase which lasted as long as stimulation continued. Stimulation at 10–20 Hz also produced a rapid initial increase in flow but at these frequencies the subsequent decline was not seen and a gradual further increase to a maintained level was observed. 3. Atropine in small doses depressed both the transient and the maintained response to low frequency stimulation but at 10–20 Hz the maintained vasodilatation was unaffected by the drug. 4. The transient increase in potassium concentration in saliva and venous blood draining the gland was not correlated with the vascular response. 5. In conclusion, further details have been provided concerning the vascular response to chorda-lingual nerve stimulation and its sensitivity to atropine. Functional vasodilatation is not secondary to potassium release and is not due to a direct interaction between rate of saliva production and rate of blood flow although the vasodilatation does appear to be related in part to the acompanying salivation.