[Expression of HSP70 induced by ketamine in the hippocampus of rat at different ages].
OBJECTIVE
This experiment was designed to explore the possible mechanism of the brain injury caused by ketamine.


METHODS
Thirty-five adult SD rats randomly divided into a control group and 6 experiment groups were given intrapertioneal injections of normal saline, 20.0, 40.0, 60.0, 80.0, 100.0, 120.0 mg/kg of ketamine respectively. Another 35 SD rats at 0-10, 11-20, 21-30, 31-45, 46-60, 61-90, 91-120 days old were allocated to 7 corresponding age groups and were given intrapertioneal injection of ketamine 80.0 mg/kg. Immunocytochemistry was used to detect HSP70 expression in rat hippocampus, and MIAS-2000 photography analytic software was chosen to analyze HSP70 expression.


RESULTS
Ketamine induced HSP70 expression in adult rat hippocampus. Below the dose of 80.0 mg/kg, ketamine induced higher level of HSP70 expression as the dose increased; however, above the dose of 80.0 mg/kg, ketamine induced lower level of HSP70 expression as the dose increased. Ketamine did not induce HSP70 expression in the rats under 20 days of age; it induced the same HSP70 expression in rats of 90 days and over; and analyses of the rats of 20-90 days revealed that the elder the rat is, the higher the HSP70 expression will be.


CONCLUSIONS
Ketamine injures the neurons of rat hippocampus and induces the expression of HSP70, and the higher the dose is given, the more serious the injury is seen; and ketamine induces higher level of HSP70 expression in adult rats than in infant rats.
Liao
Ren
R
Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China.
Wang
Quan-yun
QY
Zhang
Lan
L
Xiao
Hong
H
D000367:Age Factors; D000778:Anesthetics, Dissociative / Q000633:toxicity; D000818:Animals; D004305:Dose-Response Relationship, Drug; D005260:Female; D018840:HSP70 Heat-Shock Proteins / Q000096:biosynthesis*; D006624:Hippocampus / Q000378:metabolism*; D007649:Ketamine / Q000633:toxicity*; D008297:Male; D009474:Neurons / Q000378:metabolism; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley
D000778:Anesthetics, Dissociative; D018840:HSP70 Heat-Shock Proteins; D007649:Ketamine