Rodent neonatal bilateral carotid artery occlusion with hypoxia mimics human hypoxic-ischemic injury.
We report a new clinically relevant model of neonatal hypoxic-ischemic injury in a 10-day-old rat pup. Bilateral carotid artery occlusion and 8% hypoxia (1 to 15 mins, BCAO-H) was induced with varying degrees of injury (mild, moderate, severe), which was quantified using magnetic resonance imaging including diffusion-weighted and T2-weighted imaging at 24 h and 21/28 days. We developed a magnetic resonance imaging-based rat pup severity score and compared 3D ischemic injury volumes/rat pup severity score with histology and behavioral testing. At 24 h, hypoxic-ischemic injury was observed in 17/27 animals; long-term survival was 81%. Magnetic resonance imaging lesion volumes did not correlate with hypoxia duration but correlated with rat pup severity score, which was used to classify animals into mild (n=21), moderate (n=6), and severe (n=10) groups with average brain lesion volumes of 0.9%, 33.2%, and 56.3%, respectively. Histology confirmed lesion location and histologic scoring correlated with the rat pup severity score. We also found excellent correlation between injury severity and multiple behavioral tasks. Bilateral carotid artery occlusion and hypoxia in the P10 rat pup is an excellent model of neonatal hypoxic-ischemic injury because it induces diffuse global injury similar to the term infant. This model can produce graded injury severity, similar to that seen in human neonates, but manipulation with hypoxia duration is unpredictable.
Recker
Rebecca
R
Department of Pediatrics, School of Medicine, Loma Linda University Medical Center, Loma Linda, California 92354, USA.
Adami
Arash
A
Tone
Beatriz
B
Tian
Hui Rou
HR
Lalas
Serafin
S
Hartman
Richard E
RE
Obenaus
André
A
Ashwal
Stephen
S
D000818:Animals; D000831:Animals, Newborn; D002340:Carotid Artery Diseases / Q000473:pathology*; D004195:Disease Models, Animal; D006801:Humans; D000860:Hypoxia; D020925:Hypoxia-Ischemia, Brain / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D051381:Rats; D012720:Severity of Illness Index; D015996:Survival Rate; D013997:Time Factors