Summary
The walls of rabbit mesenteric arterioles and venules (diameter 20 to 40 pm) were
punctured with glass micropipets (tip diameter 6 to 8 pm). Thromboembolic reactions
resulting from this standardized, small mechanical vessel wall injury could be quantified
in vivo with the use of intravital video-microscopy. Following induction of the injury thrombus
growth started immediately (<0.1 s). Bleeding times were short, on the average less
than 2 s, and did not differ between arterioles and venules. The duration of the embolization
process was significantly longer in arterioles than in venules (median 101 and 17
s, respectively), and more emboli were produced in arterioles than in venules (median
6 and 1, respectively). Arteriolar thrombi were more effective in plugging the punctured
holes than venular thrombi. The differences in thromboembolic reaction between arterioles
and venules, as found in the present study, can probably not be explained by fluid
dynamic factors.
Key words
Vessel wall injury - Thrombus formation - Blood platelets - Intravital microscopy
- Fluid dynamics