摘要
目的研究热休克蛋白(Hsp-70)在脑出血(ICH)后的血肿周围脑组织的表达,及应用尼莫地平对其表达的影响,探讨尼莫地平对血肿周围缺血脑组织的保护作用。方法120只SD雄性大鼠随机分为3组:假手术组(n=20)、ICH治疗组(n=50)和ICH模型组(n=50)。按术后6,24,48,72 h和5 d分为5个亚组。采用自体股动脉取血并向大鼠尾壳核注射方法复制脑出血模型,假手术组仅进针入尾壳核不注血,ICH模型组及ICH治疗组于尾壳核处注自体动脉血50μL。ICH治疗组于造模即刻腹腔内注射尼莫地平(1.6 mg.kg-1)一次,此后每天1次;ICH模型组注入等量0.9%氯化钠溶液。于造模动物醒后由“盲”合作者根据Bederson法进行神经缺陷评分,评分≥2分入选实验。假手术组全部入选。入组实验动物按以上5个时间点腹腔注射10%水合氯醛0.5 mL.(100 g)-1,0.9%氯化钠溶液200 mL心脏灌流后迅速断头取脑,经尾壳核行冠状切片,分别行脑含水量的测定及免疫组化测定Hsp-70表达。结果①脑含水量:ICH模型组脑组织的含水量6 h变化不明显,于24 h开始升高,48~72 h逐渐达高峰,之后逐渐下降;ICH治疗组脑组织含水量的动态变化与ICH模型组一致,但各时间点的值均较低(P<0.05);两组与假手术组比较差异有显著性(P<0.05)。②血肿周围组织Hsp-70表达:脑出血后6 h可见Hsp-70阳性细胞表达,24~48 h达高峰,之后缓慢下降,至5 d仍保持较高水平未见消失;给予尼莫地平后表达增加,ICH治疗组与ICH模型组差异有极显著性(P<0.01),ICH模型组及ICH治疗组与假手术组比较差异有极显著性(P<0.01)。结论脑出血后Hsp 70表达升高,提示其与脑出血血肿周围组织损伤有一定关系。尼莫地平诱导Hsp 70表达增强,减轻ICH后血肿周围组织的细胞凋亡程度,对神经细胞起到保护作用。尼莫地平降低血肿周围组织脑含水量,具有减轻ICH后脑水肿作用。
Objective To study the effect of nimodipine on the expression of Hsp-70 in the tissue around an intracerebral hematoma(ICH) in rats so as to probe into the protective action of the drug on the ischemic brain tissue around the ICH. Methods 120 healthy male SD rats were randomly divided into 3 groups:① the sham operation group(n=20),②ICH treatment group(n=50) and ③ICH model group(n=50).For each of the rats in groups ②and ③ an ICH model was established by injecting 50 μL of autoblood taken from the animal's femoral artery into the right caudate nucleus.In rats of the sham operation group(group ①),needle was inserted into the same region as mentioned but no blood was injected.After the operation,rats of each of 3 groups were further divided into 5 equal subgroups scheduled for corresponding experimentations to be carried out 6,24,48,72 and 120 hours later.Immediately after the establishment of the ICH model,rats of the treatment group(group②) were given each an intraperitoneal injection of 1.6 mg·kg^(-1) of nimodipine followed by the same injection q.d..Rats of the model group(group ③) were given each an equivalent amount of 0.9% sodium chloride solution via the same route.Nerve defect scoring was performed by a 'blind' collaborator according to the method described by Bederson after the animals with the model awoke from the anesthesia.Animals of the ICH treatment group and model group with scores greater than 2 or equal to 2,reflecting a successful establishment of the model,were admitted into the experiment while all of the rats in the sham operation group were admitted.The admitted animals in each of the 15 subgroups described above were anesthetized with chloral hydrate and subjected to cardiac perfusion with 200 mL of 0.9%sodium chloride solution per rat followed by prompt decapitation for taking brain specimens 6,24,48,72 and 120 hours after the establishment of the model,respectively.Coronal sections across the caudate nucleus were made for the determination of the brain water content and assay of the expression of Hsp-70 with the immunohistochemical method. Results ①Brain water content: No apparent change was shown in the water content of the brain in rats of the model group 6h after the ICH.However,the water content began to increase 24h afterwards and reached its peak at 48-72 h,and then gradually declined.Dynamic changes in the brain water content in rats of the ICH treatment group followed a pattern similar to that in rats of the model group but the values at the different time points were lower(P<0.05).The values of the brain water content in rats of the model group and ICH treatment group were by and large greater than those in rats of the sham operation group.②Expression of Hsp-70 in the brain tissue around the ICH: A few cells expressing Hsp-70 were seen in the specimen from rats of the sham operation group throughout the period from 6 h to 5 d.Cells expressing Hsp-70 in the brain tissue began to appear 6 h after the establishment of the ICH model,reached the peak 24-48 h thereafter and remained at high level until 120h in rats of both the model group and ICH treatment group.However,the values obtained from rats of the latter group were significantly greater than those obtained from rats of the former group(P<0.01).The numbers of Hsp-70 expressing cells in the brain tissues from rats of he model group and ICH treatment group were also strikingly greater than those from rats of the sham operation group(P<0.01). Conclusion Increased number of cells expressing Hsp-70 after ICH may be related to the injury of the brain tissue around the hematoma.Increased expression of Hsp-70 induced by nimodipine decreased the level of apoptosis around the hematoma,thus bringing about a protective effect on the nerve cells.Decreased content of brain water in rats treated with nimodipine suggests that the drug may also alleviate brain edema.
出处
《医药导报》
CAS
2006年第10期984-987,共4页
Herald of Medicine
关键词
尼莫地平
脑出血
细胞凋亡
热休克蛋白
Nimodipine
Intracerebral hemorrhage
Apoptosis
Heat shock protein 70(Hsp-70)
