Febrile seizure, but not hyperthermia alone, induces the expression of heme oxygenase-1 in rat cortex.
BACKGROUND
Febrile seizure (FS) is the most common seizure disorders. Approximately one third of children with a febrile seizure have recurrent events. The mechanism of FS remains unclear. Heme oxygenase-1 (HO-1) is a member of the heat shock proteins family and can be induced in the brain by various stresses, including hyperthemia and seizure. This study aimed at investigating the changes of HO-1 in the cortex of rats after recurrent FS.


METHODS
FS in rats was induced ten times, once every 2 days. In a bath of warm water, developing rats were randomly divided into two groups: control group (n = 16) and warm water-treated group (n = 50). The latter group was subdivided into hyperthermia group (n = 19) and FS group (n = 23). The expression and content of HO-1 mRNA in cortex were observed using in situ hybridization and quantitative reverse transcription-polymerase chain reaction (RT-PCR). The content of HO-1 protein in cortex was measured using Western blotting.


RESULTS
HO-1 mRNA expression of cortex neurons in FS group was markedly increased in comparison with those in hyperthermia and control groups (P = 0.00), however, there was no statistic difference between hyperthermia group and control group (P = 0.16). The relative amount of HO-1 mRNA in cortex in FS group was increased by 53.13% and 96% in comparison with those in hyperthermia group and control group respectively (P = 0.00), but there was no obvious difference between the later two groups (P = 0.051). Western blotting analysis showed that the HO-1 protein content in cortex in FS group was increased by 198% and 246% in comparison with those in hyperthermia group and control group respectively (P = 0.00). There was no obvious difference in HO-1 protein content between the later two groups (P = 0.09).


CONCLUSIONS
Recurrent FS in rats can cause the increase of HO-1 mRNA and protein in cortex which may be involved in the mechanism of FS. The short-time recurrent hyperthermia can not induce the increase of HO-1 mRNA and protein.
Department of Pediatrics, First Hospital of Peking University, Beijing 100034, China. zhixian.yang@163.com
Zhi-xian
ZX
Yang
Jiong
J
Qin
Jun-bao
JB
DU
Ding-fang
DF
Bu
Xing-zhi
XZ
Chang
Ying
Y
Han
D000818:Animals; D002540:Cerebral Cortex / Q000201:enzymology*; D005334:Fever / Q000201:enzymology*; D051547:Heme Oxygenase-1 / Q000032:analysis / Q000235:genetics*; D008297:Male; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D012008:Recurrence; D003294:Seizures, Febrile / Q000201:enzymology*
D012333:RNA, Messenger; D051547:Heme Oxygenase-1