Relationship between early postoperative cognitive dysfunction and neuromodulator protein 1β in aged rats / 中华麻醉学杂志

ABSTRACT

Objective:To evaluate the relationship between early postoperative cognitive dysfunction and neuromodulator protein 1β(NRG1β) in aged rats.Methods:Pathogen-free healthy male Sprague-Dawley rats, aged 18-20 months, weighing 600-700 g, were divided into 3 groups ( n=10 each) using a random number table method: control group (group C), operation group (group O) and NRG1β group (group N). Exploratory laparotomy was performed in group O and group N. NRG1β 0.5 μg/kg was slowly injected into the lateral ventricle on 1 day before surgery in group N, while the equal volume of 0.1 mol/L phosphate buffer solution was given instead in C and O groups.Learning and memory function was assessed using Morris water maze test performed at day 3 after operation.The rats were then sacrificed, and the hippocampi were removed for determination of the expression of nuclear factor kappa B (NF-κB) p65 (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 C, the postoperative escape latency was significantly prolonged, the expression of NF-κB p65 was up-regulated, and the contents of IL-1β and TNF-α were increased in group O and group N ( P<0.05). Compared with group O, the postoperative escape latency was significantly shortened, the expression of NF-κB p65 was down-regulated, and the contents of IL-1β and TNF-α were decreased in group N ( P<0.05). Conclusion:NRG1β is involved in the endogenous protective mechanism of early postoperative cognitive dysfunction probably by inhibiting the activation of NF-κB pathway and inhibiting inflammatory responses in aged rats.