AJP - Heart and Circulatory Physiology, Vol 248, Issue 3 318-H323, Copyright © 1985 by American Physiological Society
Distribution of blood platelets flowing in arterioles
G. J. Tangelder, H. C. Teirlinck, D. W. Slaaf and R. S. Reneman
The distribution of blood platelets flowing in arterioles (21-35 microns)
of the mesentery of anesthetized rabbits was studied using intravital
fluorescence microscopy. Sites were selected without upstream branch points
within at least 10 vessel diameters. The distribution was determined by
counting in flashed video frames the number of platelets present in each of
six equal segments across the vessel. Only platelets were counted that
could be localized objectively within a thin optical section around the
median plane of the vessel. It could be shown that differences in counting
volume between the six segments were negligible. Because of the use of
flashed pictures (flash duration less than 0.1 ms; interval 180 ms), the
method is independent of differences in velocity over the cross-sectional
area of the vessel. In all measurements (15 sites in 13 vessels in 10
animals) the distribution was nonuniform, the wall segments containing the
highest platelet numbers. The general distribution as calculated from all
measurements (total platelet number 6,571) and expressed in percentages was
found to be 23.0, 14.6, 12.5, 12.1, 13.6, and 24.2.
