Ketamine improves survival in severe burn injury in rats via the expression of heat shock protein 70

Abstract Ketamine, a general anesthetic, has been shown to elicit the heat-shock response (HSR) in some of the animal models. We examined whether ketamine improves survival in severe burn injury in rats via the expression of heat shock protein 70. 124 male Wistar rats were randomly divided into three groups: a control group (group C, n  = 20), burned group (group B, n  = 52), and burned + ketamine group (group K, n  = 52). The rats in groups B and K had full-thickness burns of 30% of their total body surface. The rats in group K were treated with ketamine (40 mg/kg, i.m.) 15 min after injury, and those in group B were injected with saline at the same volume. After the rats were euthanized, HSP70 expression in myocardium and brain samples was examined by Western blot analysis. Survival status was evaluated for the rats not euthanized. After 10 days, survival rate of rats in group K was higher than that of group B (70% versus 30%). Western blot analyses revealed that HSP70 protein expression in myocardium in response to ketamine administration is stronger than that in response to saline administration at 3 h (158% versus 65%) and 6 h (165% versus 68%). Compared with that in group B, ketamine strongly increased HSP70 protein expression level in cerebral tissue at 3 h and 6 h (79% versus 51%, at 3 h; 123% versus 98%, at 6 h). We concluded that ketamine therapy improves survival in severe burn injury via the expression of heat shock protein 70 in myocardial and cerebral tissues.