Videomicroscopic methods with off-line analysis of microcirculatory paramet
ers by multifunctional computer-assisted image analysis systems have signif
icant advantages for in vivo microvascular research. A limitation of these
methods is, however, that red blood cell velocities (V-RBC) exceeding 2 mm/
s cannot be measured using standard video framing rates, In the present stu
dy, a high-speed video camera, recording up to 600 frames per seco nd, was
incorporated in the set-up, and VRBC was measured off-line with the line-sh
ift-diagram method. The aim of this study was to test the reproducibility a
nd validity of the method using a high-speed video camera and to evaluate i
ts applicability in vivo, VRBC were measured in arterioles of the split hyd
ronephrotic kidney. The intra- and interindividual variability was small fo
r V-RBC below 40 mm/s. The validity of the method was tested using the mass
conservation principle and found to be at least as good as that of the dua
l-slit photometric technique. The present approach extends the application
of videomicroscopy coupled to image analysis systems to the analysis of hig
h VRBC Copyright (C) 2000 S.Karger AG, Basel.