纳洛酮抗家兔颅脑损伤后细胞凋亡及其自由基机制的实验研究

The effect of naloxone on apoptosis of neuron after severe brain injury and its mechanisms

目的观察纳洛酮对严重颅脑损伤后神经细胞凋亡和Caspase-3表达及血红细胞内超氧化物歧化酶(SOD)活性及脂质过氧化物(LPO)含量的影响,探讨纳洛酮抗神经细胞凋亡的Caspase-3及自由基机制。方法选用健康普通家兔随机分成对照组、大剂量组及小剂量组,分别于致伤后给0.9%氯化钠注射液及大小剂量纳洛酮腹腔注射,在致伤后0h、6h、1d、3d、7d、11d和15d检测血红细胞内SOD活性(自氧化抑制法)及LPO含量(硫代巴比妥酸反应产物比色分析法),在致伤后15d检测脑组织中凋亡神经细胞(TUNEL法)及Caspase-3表达阳性神经细胞(SP法)。结果大小剂量组家兔脑组织凋亡及Caspase-3表达阳性神经细胞数量显著少于对照组(P<0.05);在7个时间段,大小剂量组与对照组之间血红细胞内SOD活性和LPO含量差异没有统计学意义(P>0.05)。结论纳洛酮可降低Caspase-3的表达,从而抑制颅脑损伤后神经细胞凋亡,而自由基可能未参与作用过程。

Objective To investigate the effect of naloxone on apoptosis of neuron after severe brain injury and its possihle mechanism. Methods Sixty rabbits were randomly divided into control group, high dose group and small dose group; the animals in each group received intraperitoneal administration of N.S., high dosage and low dosage of naloxone after brain trauma. Venous blood was drawn in Oh, 6h, 1d, 3d, 7d, 11d and 15d, and the apoptosis of neuron and expression of Caspase-3 was detected by immunohistoehcmistry; the concentrations of SOD and LPO in erythrocytes were determined by spectrophotometry. Results The number of apoptotic nervous cells and Caspase-3 positive cells in high dose or low dose group was significantly less than those in control group in 15d （P〈0.05）. There was no significant difference among three groups in the values of SOD and LPO at all time points （P〉0.05）. Conclusion Naloxone may attenuate the apoptosis of neurnn after brain injury through the inhibiting expression of caspase-3 but not involvement of free radical.