Nutrient and shunt flow responses to vidian nerve stimulation in nasal and facial tissues of the dog.

The potency of parasympathetic vasomotor efferent nerves in controlling blood flow of the face and nose was indicated by the following features attributed to the maxillary artery and their vascular compartments in dogs. Electrical stimulation of the vidian nerve induced a frequency-dependent increase in maxillary flow, which was due to a significant decrease in resistance to flow in nutrient and shunt vessels. Pronounced increases in perfusion rates mainly occurred in evaporative tissues of the nose, in particular the naso-maxilloturbinates and alar fold during vidian nerve stimulation, while those, for example, of the skin remained unchanged. Adrenergic and subsequent cholinergic blockade left the response pattern of maxillary flow to vidian nerve stimulation basically unaffected. Both nutrient and shunt flows contributed to the parasympathetically induced increases in maxillary flow while responses were compartmentalized similar to that found in untreated animals. Apart from sympathetic vasoconstrictor inputs, these results show that cholinergic and non-cholinergic parasympathetic vasodilator inputs contribute to the adjustment of vasomotor tone in the maxillary vascular bed.