环化酶激活剂对周围神经损伤大鼠脊髓背根节感觉神经元的保护作用

Protective effect of cyclase activators on sensory neurons in dorsal root ganglia of rats after peripheral nerve injury

目的:观察腺苷、前列腺素E1以及Zn2+等环化酶激活剂对周围神经损伤后脊髓背根感觉神经元的保护作用,并与神经生长因子的作用进行比较。方法:实验于1996-07在吉林医学院神经生物实验室进行。取SD大鼠60只随机分为6组(n=10):①前列腺素E1组:建立右侧坐骨神经夹毁模型,术后4h术侧股二头肌注射前列腺素E1溶液0.05mg/kg,1次/d,定时给药,连续14d。②腺苷组:造模同前,注射腺苷溶液20mg/kg,注射时间和部位同前列腺素E1组。③高锌组:造模同前,术前10d开始喂以高锌饲料(饲料锌含量为52.7mg/kg)。④神经生长因子组:造模同前,术侧后肢足跖皮下注射β神经生长因子溶液0.1mg/kg,注射时间同前列腺素E1组。⑤模型组:造模同前,注射0.5mL灭菌生理盐水,注射时间和部位同前列腺素E1组。⑥假手术组:手术但不夹毁神经,余同模型组。在造模后21d,取大鼠L5背根节用图像分析法观测细胞数、核偏心率及核等圆径。结果:经补充60只大鼠进入结果分析。①背根节细胞数:腺苷组及前列腺素E1组的细胞存活数均低于假手术组和神经生长因子组(P<0.05);各组背根节大、中、小细胞构成比例无差别(P>0.05),大细胞损失最大,其细胞平均数为假手术组的57.5%;中细胞损失最小,其细胞平均数为假手术组的89%。②核偏心率:神经生长因子组及高锌组与假手术组无差别(P>0.05),腺苷组低于模型组(P<0.05),前列腺素E1与模型组无差别(P>0.05)。③核等圆径:神经生长因子组及高锌组与加手术组无差别(P>0.05),腺苷组低于模型组(P<0.05),前列腺素E1与模型组无差别(P>0.05)。结论:腺苷等环化酶激活剂对周围神经损伤后的脊髓背根节神经元均有显著的保护作用,其中Zn2+的保护效应与神经生长因子无差别,腺苷、前列腺素E1保护效应低于神经生长因子。

AIM： To observe the protective effects of cyclase activators [such as adenosine, prostaglandin E1 （PGE1） and Zn^2＋, etc] on the sensory neuron of dorsal root ganglion （DRG） after the peripheral nerve injury, and compare the effects with that of nerve growth factor （NGF）. METHODS： The experiment was conducted at the Neurobiology Laboratory of Jilin Medical College in July 1996. A total of,60 SD rats were divided randomly into six groups, with 10 in each group： ①PGEI group： The right sciatic nerve injury models were established by the sciatic nerve crush operation in rats, and 0.05 mg/kg PGEI solution was injected into the biceps femoris at 4 hours after operation, once a day and continuously for 14 days. ②Adenosine group： The model establishments were same as above, and 20 mg/kg adenosine solution was injected, with the same injected time and locus as PGEI group. ③High Zn^2＋ group： The model establishments were same as above, and the high Zn^2＋ feed （containing 52.7 mg/kg Zn^2＋） were given from 10 minutes before operation. ④NGF group： The model establishments were same as above, and 0.1 mg/kg NGFβ solution＇ was injected subcutaneously into the metatarsus of hindlimb, with the same injected time as PGEI group. ⑤Model group： The model establishments were same as above, and 0.5 mL sterilized saline was injected, with the same injected time and locus as PGEI group. ⑥Shamoperated group： The operation was performed without the nerve injury, and other interventions were same as the model group. On the 21^nt day after the model establishments, DRG was used to observe the number of DRG cells, eccentricity of nucleus and equal radius of nucleus with the imaging analysis. RESULTS： Totally 60 rats were involved in the result analysis after supplement. ①Number of DRG cells： The numbers of survival cells were lower in the adenosine group and PGEI group than in the sham-operated group and NGF group （P 〈 0.05）; There was no difference in the cellularity proportion of maximum, medium and minimum levels （P 〉 0.05）. The maximum cells lost most with the mean of 57.5% in the sham-operated group and the medium cells lost least with the mean of 89% in the shamoperated group. ②Eccentricity of nucleus and equal radius of nucleus： There was no difference between NGF group, high Zn^2＋ group and shamoperated group, between PGE1 group and model group （P 〉 0.05）. However, the eccentricity of nucleus and equal radius of nucleus were lower in the adenosine group than in the model group （P 〈 0.05）. CONCLUSION： The cyclase activators have remarkable protective effects on DRG neuron after the peripheral nerve injury, and there was no difference in the protections of Zn^2＋ and NGF. The protective effects of adenosine and PGEI are lower than that of NGF.