Effect of surgical trauma on the expression of COX-2 and PGE2 in hippocampus in aged rats / 中华麻醉学杂志

ABSTRACT

Objective To investigate the effect of surgical trauma on the expression of COX-2 and PGE2in the hippocampus in aged rats. Methods Forty-five 18-month-old male SD rats weighing 500-600 g were randomly divided into 3 groups (n = 15 each) group Ⅰ control (group C); group Ⅱ anesthesia (group A) and group Ⅲ surgery + anesthesia (group S). Anesthesia was induced by intraperitoneal 1% pentobarbital sodium 50 mg/kg in group A and S. The animals underwent appendectomy and splenectomy under anesthesia in group S.Cognitive function was assessed by open field test and Y-mase test on the 1st, 3rd and 7th day after anesthesia and surgery (T1-3). The animals were sacrificed after behavior tests at T1.2.3 and the hippocampi were removed for determination of the expression of COX-2 mRNA (by RT-PCR) and PGE2 content (by ELISA). Results The time the animal spent in the central square was significantly prolonged, the number of crossing grid and standing on the back legs and the number of right response were decreased, the total reaction time was prolonged and the COX-2mRNA expression at T1 and PGE2 content in the hippocampus were increased at T1,2 in group S as compared with group C and A. There was no significant difference in the variables mentioned above between group C and A. Conclusion Surgical trauma can induce early postoperative cognitive dysfunction through up-regulation of COX-2 mRNA expression and by increasing PGE2 content in the hippocampus in aged rats.