丙泊酚麻醉对老龄大鼠认知功能和海马神经元γ-氨基丁酸A受体表达的影响

Effect of propofol on cognitive function and expression of hippocampal neuronalγ-aminobutyric acid receptor in aged rats

目的观察丙泊酚麻醉对老龄大鼠认知功能及海马神经元γ-氨基丁酸A(GABA)受体表达的影响。方法50只SD老年大鼠随机分为丙泊酚组和对照组,每组25只。丙泊酚组大鼠腹腔注射1%丙泊酚中/长链脂肪乳注射液6 mL/kg,对照组腹腔注射等体积的生理盐水。麻醉后1 d进行Morris水迷宫实验,分别采用HE染色和尼氏体染色观察海马区神经细胞及尼氏体(Nissl体)形态学变化,Western Blot检测GABA蛋白量表达。结果麻醉后,2组大鼠肛温、心率、呼吸频率、血氧饱和度比较,差异均无统计学意义(P>0.05)。随着实验时间的延长,2组大鼠逃逸潜伏期、总里程数逐渐减小,丙泊酚组大鼠各时间点逃逸潜伏期、总里程均高于对照组,差异有统计学意义(P<0.05)。丙泊酚组大鼠穿越平台区域次数、时间小于、短于对照组,差异有统计学意义(P<0.05)。对照组海马区Nissl体存在于细胞浆及树突,染色较深,神经细胞排列整齐,形态规则;丙泊酚组Nissl体消失,神经细胞数量减少,细胞核破裂、丢失。丙泊酚组大鼠海马GABA蛋白表达量低于对照组,差异有统计学意义(P<0.05)。结论丙泊酚对大鼠认知功能有影响,并与海马区GABA的表达相关。

Objective To observe the effect of propofol on cognitive function and expression of hippocampal neuronalγ-aminobutyric acid(GABA)receptor in aged rats.Methods Totally 50 elderly SD rats were randomly divided into propofol group and control group,with 25 rats in each group.Rats in the propofol group were injected with 6 mL/kg 1%propofol medium/long chain fat emulsion injection through abdominal cavity,while rats in the control group was injected with equal volume of normal saline through abdominal cavity.Morris water maze experiment was carried out at 1 day after anesthesia,the morphologic changes of hippocampal neurons and Nissl body were observed by HE staining and Nissl staining respectively,and the expression of GABA protein was determined by Western blot.Results After anesthesia,there were no significant differences in anal temperature,heart rate,respiratory rate and blood oxygen saturation between the two groups(P>0.05).With the extension of the experimental time,the escape latency and the total mileage of rats in both groups decreased gradually,and the escape latency and the total mileage of the rats in the propofol group were significantly higher than those in the control group(P<0.05).The times and duration of rats crossing the platform area in the propofol group were significantly less and shorter than those in the control group(P<0.05).In the control group,Nissl bodies were found in the cytoplasm and dendrites,with deep staining and regular arrangement of nerve cells.In the propofol group,Nissl bodies disappeared,the number of nerve cells decreased,and the nucleus ruptured and lost.The expression of GABA protein in hippocampus of the propofol group was significantly lower than that of control group(P<0.05).Conclusion Propofol has an effect on cognitive function in rats,which is related to the expression of GABA in hippocampus.