Nasal resistance and nasal blood flow in postural changes.

Posture greatly influences nasal resistance. To investigate whether nasal blood flow synchronizes with nasal resistance during changes in posture, correlation coefficients were calculated based on findings from both nasal cavities in 14 normal subjects. There was no correlation between nasal resistance and nasal blood flow, except in the left nasal cavity of one subject. Nasal blood flow was measured by a laser Doppler flowmeter, which detects the blood flow in the superficial part of the nasal mucosa. Nasal resistance is regulated mainly by capacitance vessels located in the deeper part of the nasal mucosa. Therefore, the dissociation in nasal resistance and blood flow responses to postural changes noted in our study suggests that vessels in different parts of the nasal mucosa respond differently to this same stimulus.