Changes in expression of hippocampal HSP70 during postoperative cognitive dysfunction in aged rats / 中华麻醉学杂志

ABSTRACT

Objective:To evaluate the changes in the expression of hippocampal HSP70 during postoperative cognitive dysfunction in aged rats.Methods:Twelve pathogen-free healthy male Sprague-Dawley rats, aged 18 weeks, weighing 500-650 g, were divided into 2 groups ( n=6 each) using a random number table method: old control group (group O) and old surgery group (group OS). Another 12 pathogen-free healthy male Sprague-Dawley rats served as control and divided into 2 groups ( n=6 each) according to a random number table method: adult control group (group A) and adult surgery group (group AS). Exploratory laparotomy was performed in group AS and group OS.Morris water maze test was performed at 3 days after operation, and then the rats were sacrificed, and the hippocampi were removed for determination of the expression of heat shock protein 70 (HSP70) (by Western blot) and contents of interleukin-1beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) (by enzyme-linked immunosorbent assay). Results:Compared with group A, the expression of HSP70 was significantly up-regulated ( P<0.05), and no significant change was found in the other indices in group AS ( P>0.05). Compared with group O, the escape latency was significantly prolonged, the frequency of crossing platform was decreased, the contents of IL-1β and TNF-α were increased, and the expression of HSP70 was up-regulated in group OS ( P<0.05). Compared with group AS, the escape latency was significantly prolonged, the frequency of crossing platform was decreased, the contents of IL-1β and TNF-α were increased ( P<0.05), and no significant change was found in the expression of HSP70 in group OS ( P>0.05). Conclusion:HSP70 expression in hippocampi is up-regulated during postoperative cognitive dysfunction and is helpful in inhibiting the inflammatory response and exerting endogenous neuroprotective effect in aged rats.