Expression of inducible nitric oxide synthase and cyclooxygenase-2 mRNA in brain damage induced by lipopolysaccharide and intermittent hypoxia-ischemia in neonatal rats.
OBJECTIVE
The purpose of the present study was to examine the effect of lipopolysaccharide (LPS) and intermittent hypoxia-ischemia (HI) on brain damage in neonatal rats.


METHODS
Seven-day-old Wistar rats were injected with saline or LPS (1 mg/kg), and then underwent left common carotid artery ligation followed by a repetitive 8% hypoxia (2.0-4.5 min) at 10-min intervals 10 times. The rats were divided into three groups: LPS with HI (LPS/HI, n = 46), saline with HI (HI alone, n = 42) and LPS alone (n = 16). Seven days later, brains were assessed for neuronal damage and inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) mRNA expression.


RESULTS
Neuronal damage in the ligated side was significantly higher in LPS/HI than the other two groups (P < 0.01). The expression of iNOS and COX-2 mRNA was observed in the affected brain in LPS/HI, which corresponded well to histologic neuronal loss.


CONCLUSIONS
LPS enhanced intermittent HI brain damage in immature animals. The expression of iNOS and COX-2 mRNA is considered to be associated with perinatal brain injury processes.
Yang
Li
L
Department of Obstetrics and Gynecology, Miyazaki Medical College, University of Miyazaki, Kiyotake, Miyazaki, Japan.
Sameshima
Hiroshi
H
Yamaguchi
Masatoshi
M
Ikenoue
Tsuyomu
T
D000818:Animals; D000831:Animals, Newborn; D001921:Brain / Q000201:enzymology; D001927:Brain Diseases / Q000139:chemically induced / Q000201:enzymology / Q000209:etiology*; D017536:Carotid Artery, Common / Q000601:surgery; D051546:Cyclooxygenase 2; D004926:Escherichia coli; D015870:Gene Expression; D020925:Hypoxia-Ischemia, Brain / Q000201:enzymology*; D017403:In Situ Hybridization; D008026:Ligation; D008070:Lipopolysaccharides; D019001:Nitric Oxide Synthase / Q000235:genetics*; D052247:Nitric Oxide Synthase Type II; D011451:Prostaglandin-Endoperoxide Synthases / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar
D008070:Lipopolysaccharides; D012333:RNA, Messenger; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496318:Nos2 protein, rat; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases