Effects of Different Doses of BDNF on Postoperative Cognitive Function in Aged Rats Undergoing Abdominal Surgery

Abstract

Objective: To investigate the effects of different doses of BDNF on postoperative cognitive function in aged rats undergoing abdominal surgery. Methods: 72 aged healthy male SD rats of SPF grade were selected. According to the random number table method, the rats were randomly divided into the control group, model group, low dose BDNF injection group, and high dose BDNF injection group, with 18 rats in each group. The model group, low dose group, and high dose group underwent abdominal surgery after anesthesia, and 5?L/time of BDNF was intranasally administered to the rats in the low dose and high dose groups 6 hours after abdominal surgery, of which the dose of the low dose group was 0.1 g/L, while that of the high dose group was 0.2 g/L. The drug was administered alternately through both nostrils, with an interval of 2 minutes each time, for 5 times. The control group did not undergo surgery after anesthesia. The escape latency and swimming distance of the four groups of rats were compared before surgery, the first day, the third day, and the seventh day after surgery; similarly, the BDNF protein expression level in the hippocampus of the four groups of rats was compared on the first day, the third day, and the seventh day after surgery. Results: The escape latency and swimming distance of the control group were not statistically significant on the first day, the third day, and the seventh day after surgery, p > 0.05; the escape latency and swimming distance of the model group, low dose group, and high dose group on the first day, the third day, and the seventh day after surgery were statistically significant, p < 0.05. Before surgery, the escape latency and swimming distance of the four groups were not statistically significant, p > 0.05; on the first day, the third day, and the seventh day after surgery, the escape latency and swimming distance of the model group > low dose group > high dose group > control group, p < 0.05. The BDNF protein expression level in the hippocampus of the control group on the first day, the third day, and the seventh day after surgery showed no statistical significance p > 0.05; the expression level of BDNF protein in the hippocampus of the model group, low dose group, and high dose group on the first day, the third day, and the seventh day after surgery was statistically significant, p < 0.05. On the first day, the third day, and the seventh day after surgery, the expression level of BDNF protein in the hippocampus of the model group < low dose group < high dose group < control group, p < 0.05. Conclusion: Compared with 0.1 g/L of BDNF, 0.2 g/L of BDNF can improve the postoperative cognitive function of aged rats undergoing abdominal surgery.