神经营养因子修复神经组织机制的研究:脑细胞生长肽对豚鼠耳蜗毛细胞内酸性磷酸酶的影响

背景脑细胞生长肽(cerebrocellular growth peptide,CCGP)对庆大霉素引起的耳蜗毛细胞内酸性磷酸酶(acid phosphatase,ACP)的变化是否有影响?对受损耳蜗组织是否有促进修复的作用?目的观察CCGP对庆大霉素引起的耳中毒豚鼠ACP的影响.设计随机对照研究.地点和材料实验地点泰山医学院听觉研究室.选用健康杂色豚鼠40只,对照组10只,肌肉注射生理盐水1 mL/(kg·d);庆大霉素组15只,肌肉注射硫酸庆大霉素80 mg/(kg·d);CCGP组15只,肌肉注射硫酸庆大霉素同庆大霉素组,并肌肉注射CCGP 1 mg/(kg·d).各组用药25d.方法用脑干听觉诱发电位(brainstem auditory evoked potential,BAEP)和组织化学方法检测动物听阈的变化和耳蜗毛细胞ACP显色变化.主要观察指标各组动物BAEP反应阈值和ACP显色变化.结果用药前BAEP反应阈值dB(peSLP)]生理盐水组32.62±2.33,庆大霉素组31.87±2.63,CCGP组32.56±2.39.用药后BAEP反应阈值均有不同程度的升高,用药后25 d BAEP反应阈值生理盐水组32.81±2.48,庆大霉素组56.73±17.21,CCGP组42.87±9.95,庆大霉素组、CCGP组与生理盐水组比较,差异均有显著性意义(t=3.113,4.335,P均＜0.01),CCGP组与庆大霉素组比较,差异有显著性意义(t=2.700,P＜0.05).ACP显色变化生理盐水组毛细胞ACP染色呈棕褐色,毛细胞排列整齐.庆大霉素组ACP变化显著,毛细胞显色失明显;CCGP组ACP显色变化较轻,两组铺片显示有明显差别.结论CCGP能降低庆大霉素的耳毒性,减轻由于溶酶体的破坏溢出的ACP引起的毛细胞的损伤.

A study on the mechanism of neurotrophic factors for repair of nerve tissue:effects of cerebrocellular growth peptide on acid phosphatase of hair cells in cochlea of gentamicin induced ototoxic guinea pigs

BACKGROUND: Cerebrocellular growth peptides(CCGP) can affect the change of acid phosphatase(ACP) in cochlea induced by gentamicin and accelerate the repair of injured cochlear tissue is unknown. And whether inter neurotrophins have a coordinated effect is also unclear.OBJECTIVE: To investigate the effects of CCGP on ACP in cochlear hair cells of GM-induced ototoxic guinea pigs.DESIGN: A randomized controlled trial.SETTING and MATERIALS: The experiment was completed in the Department of Audition, Taishan Medical College. Forty healthy parti-colored guinea pigs were selected and randomized into control group of 10 guinea pigs through intramuscular injection of 1 mL/(kg·d) saline, gentamicin group of 15 guinea pigs intramuscularly injected with 80 mg/(kg·d)gentamicin, and CCGP group intramuscularly injected with 1 mL/(kg·d)CCGP. The duration of administration was 25 days.METHODS: The hypoacusis severity and enzymatic activity in the cochlear hair cells were examined by brainstem auditory evoked potential (BAEP) and histochemistry, respectively.MAIN OUTCOME MEASURES: BAEP reaction thresholds and changes of ACP in the cochlear hair cells.RESULTS: Before treatment the BAEP reaction thresholds were (32.62 ±2.33) dBpeSLP for the saline group, (31.87 ± 2. 63) dBpeSLP for the gentamicin group and(32.56 ± 2.39) dBpeSLP for the CCGP group. BAEP reaction thresholds were elevated at different levels after treament. Twenty-five days after treatment, the BAEP reaction thresholds were (32.81 ± 2. 48),(56.73±17.21) and(42.87±9.95) dBpeSLP for the three groups respectively. There were significant differences between the control group and gentamicin and CCGP groups( t =3. 113, 4. 335, P ＜ 0. 01), and between the gentamicin group and CCGP group( t = 2. 700, P ＜ 0. 05). In the control group, the hair cells presented dark brown stained by ACP histochemical staining and arranged in order. ACP histochemical reaction showed that the color disappeared in the hair cells of the gentamiein group. In the CCGP group, no obvious change was found in ACP level, and there was a significant difference between the gentamicin and CCGP groups.CONCLUSION: CCGP can reduce gentamicin-induced ototoxicity and autolytic lesion of hair cells induced by destroyed lysosome.