Laser-Doppler flowmetry compared to intravital microscopy for assessment of blood flow in the nasal mucosa of the rabbit.

Laser-Doppler flowmeter (LDF) studies of the rabbit nasal mucosal microcirculation were compared with intravital videomicroscopy and with flow measured in single blood vessels in order to evaluate the applicability of the LDF technique. Access to the nasal mucosa for a microscope objective was gained surgically through the maxilla. Transillumination for microscopy was achieved through a prism inserted on the contralateral side of the septal cartilage. Blood flow changes were induced by the inhalation of N2, CO2 and O2 and by topically applying the vasoconstricting alpha-adrenoceptor agonist oxymetazoline. The effects were registered by LDF and direct visual observation. Flow in veins and capillaries was calculated using on-line cross-correlation, and off-line a computerized video-analysis system. LDF did not correlate to flow in single veins or capillaries but agreed well with the visual impression. LDF is considered a valuable method for the assessment of over-all blood flow changes in the nasal mucosa.