Spontaneous rhythmic vasomotion of arterioles and laser Doppler flowmetry

Abstract

Synchronous measurements of fluctuations of ear skin blood flow (SBF) and blood flow rate (FR) in a single arteriole in a rabbit ear chamber (REC) has been studied by utilizing laser Doppler flowmetry and a newly developed method, respectively. FR's were calculated with inside diameters (ID) and red blood cell velocities (RBCV) in arterioles in the REC. ID and RBCV were simultaneously measured by a video image analysis system and a dual - photometric method with a crosscorrelation analysis, respectively. Patterns of the flow motion of SBF and FR during vasomotion were classified into the following two oscillations types. One type was relative high frequency and small amplitude oscillations. Another type was low frequency and large amplitude oscillations. Low frequency oscillations superimposed on high frequency oscillations. When we observed high frequency oscillations, there was a poor correlation between SBF and FR. When low frequency oscillations of FR was only showed, we observed a clear correlation between SBF and FR. We suggest that high frequency oscillations to be local non-neurogenic vasomotion and low frequency oscillations to be pure neurogenic origin.