Inhibitory effect of activated protein C on cerebral vasospasm after subarachnoid hemorrhage in the rabbit.
This study investigated whether activated protein C (APC) improves the cerebral vasospasm in an experimental subarachnoid hemorrhage that was produced by the intracisternal injection of autologous blood. Male rabbits were divided into the following four groups: APC 0.1-and 0.5-mg groups, in which 0.1 and 0.5 mg APC were injected into the cisterna magna, respectively; a placebo group, in which saline was injected instead of APC; and a sham operation group that did not get injections of autologous blood, APC, and saline. On day 2, amount of clot in the basal cistern was significantly (p < 0.01) decreased in the APC 0.5-mg group. Percent diameter of the basilar artery on day 2 to that before injecting the blood was angiographically determined as 97.1 +/- 3.8% in the APC 0.5-mg group, which was significantly (p < 0.001) greater than the corresponding value in the placebo group (74.8 +/- 3.4%). The impaired endothelium-dependent relaxation following subarachnoid hemorrhage was normalized in the APC 0.5-mg group (p < 0.0001). These results suggest that APC would improve cerebral vasospasm following subarachnoid hemorrhage, possibly by decreasing the amount of subarachnoid clot and normalizing the impaired nitric oxide production/release.
Mizuno
Yusuke
Y
Department of Neurosurgery, School of Medicine, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo 113-8519, Japan.
Azuma
Hiroshi
H
Ito
Yoshifumi
Y
Isotani
Eiji
E
Ohno
Kikuo
K
Hirakawa
Kimiyoshi
K
D000818:Animals; D000925:Anticoagulants / Q000494:pharmacology / Q000627:therapeutic use*; D001488:Basilar Artery / Q000000981:diagnostic imaging / Q000187:drug effects / Q000502:physiology; D004195:Disease Models, Animal; D008297:Male; D011486:Protein C / Q000494:pharmacology / Q000627:therapeutic use*; D011817:Rabbits; D011859:Radiography; D013345:Subarachnoid Hemorrhage / Q000000981:diagnostic imaging / Q000188:drug therapy*; D014661:Vasoconstriction / Q000187:drug effects / Q000502:physiology; D020301:Vasospasm, Intracranial / Q000000981:diagnostic imaging / Q000188:drug therapy*
D000925:Anticoagulants; D011486:Protein C