Cerebral blood flow distribution and hypoxic-ischemic brain damage in newborn rats.
OBJECTIVE
Our purpose was to assess the cerebral blood flow distribution and resulting grade of hypoxicischemic brain damage in newborn rats.


METHODS
Seven-day-old Wistar rats (n = 75) underwent left common carotid artery ligation followed by 2 hours hypoxia (8% oxygen in nitrogen) at 33 degrees C. The control animals were exposed to hypoxia without ligation (n = 8). Colored microspheres of 15 microm in diameter were administered into the left cardiac ventricle percutaneously at the end of hypoxia. They were killed 24 hours after induced injury. Brain sections 2 mm in thickness were removed for microtubule-associated protein 2 (MAP-2) staining, and remaining parts were separated into left and right hemispheres for counting the microspheres. The blood flow distribution to the ligated side was expressed as the difference from the non-ligated control side. Severity of MAP-2 disappearance was ranked as normal, mild or severe.


RESULTS
In the control rats, there was no loss of MAP-2 staining. The blood flow equally distributed into both cerebral hemispheres. The cerebral blood flow distribution on the side of carotid artery ligation decreased by 44.7 +/- 21.9% in the mildly damaged group and 65.8 +/- 16.8% in the severely damaged group.


CONCLUSIONS
The greater the percentage difference of blood flow distribution from the non-ligated side, the more severe the brain damage.
Xia
Yi Xin
YX
Department of Obstetrics and Gynecology, Miyazaki Medical College, Miyazaki, Japan.
Sameshima
Hiroshi
H
Ikeda
Tomoaki
T
Higo
Takafumi
T
Ikenoue
Tsuyomu
T
D000818:Animals; D000831:Animals, Newborn; D001921:Brain / Q000098:blood supply*; D005260:Female; D020925:Hypoxia-Ischemia, Brain / Q000503:physiopathology*; D007150:Immunohistochemistry; D008863:Microspheres; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D011247:Pregnancy; D051381:Rats; D017208:Rats, Wistar; D012039:Regional Blood Flow
D008869:Microtubule-Associated Proteins