Stroke, Vol 18, 796-800, Copyright © 1987 by American Heart Association
RL Haberl, ML Heizer and EF Ellis
Our previous experiments have shown that thromboxane A2 is a strong
contractor of cerebral arterial smooth muscle strips. The objective of
these experiments was to determine if U 46619, a stable thromboxane A2
mimetic, affects the cerebral microcirculation in vivo. Pial arteriole
diameter in rabbits and rats was measured with a microscope using the
closed cranial window technique. Topical application of 10(-11) to 10(- 6)
M U 46619 induced dose-dependent arteriole vasoconstriction in both
species. In rabbits and rats the maximum vasoconstriction was 9.7 +/- 1.3%
(mean +/- SEM) and 14.0 +/- 0.5%, respectively. In rats, 10(-7) and 10(-6)
M U 46619 induced intravascular platelet aggregation accompanied by a
further decrease in diameter and transient occlusion of the arterioles and
venules. U 46619 had no significant effect on rabbit pial arterioles that
were predilated by hypercapnia or hypercapnia plus hypoxia. Our data
suggest that in animals with a normal vasculature, thromboxane A2 may be a
moderate constrictor of cerebral arterioles and that this constrictor
effect is prevented by hypercapnia and hypoxia.
ARTICLES
Effect of the thromboxane A2 mimetic U 46619 on pial arterioles of rabbits and rats
This article has been cited by other articles:
 |
|
 |
|
  M. Uchida, H. Iida, M. Iida, and S. Dohi Changes in Cerebral Microcirculation During and After Abdominal Aortic Cross-Clamping in Rabbits: The Role of Thromboxane A2 Receptor Anesth. Analg., March 1, 2003; 96(3): 651 - 656. [Abstract] [Full Text] [PDF]
|
|