间歇运动对大鼠骨骼肌凋亡基因Bax、Bcl-2及相关因素的影响

通过比较间歇运动中不同类型骨骼肌中氧自由基,线粒体Ca2 含量代谢情况,Bax,Bcl-2凋亡基因表达的差异,来探讨间歇运动导致骨骼肌细胞凋亡的可能机制。24只SD大鼠,随机分为安静对照组(8只),一次间歇运动组(8只),长期间歇训练组(8只)。运动后24 h取比目鱼肌和胫骨前肌,采用RT-PCR方法检测Bax,Bcl-2基因表达情况,并测定组织中SOD活性、MDA含量和线粒体钙含量。结果表明:1)一次间歇运动组胫骨前肌中Bax/Bcl-2比值显著升高(P<0.05),且Bcl-2表达显著低于长期间歇训练组(P<0.05)。2)运动后,胫骨前肌和比目鱼肌中SOD活性均升高了,但仅一次间歇运动后胫骨前肌SOD活性较安静时增加具有显著性(增加48%,P<0.05)。3)一次间歇运动和长期间歇训练后胫骨前肌中MDA含量均非常显著性高于安静对照组(P<0.01)。4)一次间歇运动后,胫骨前肌线粒体Ca2 含量较安静时增加100%,差异非常显著(P<0.01),同时也显著性高于比目鱼肌中线粒体Ca2 含量(P<0.05)。结论:1)一次高强度的间歇运动可能主要通过快肌中Bax表达增强,Bcl-2表达减弱,氧自由基的升高,粒体内钙超载,共同致运动能力下降。2)长期间歇训练可能通过增强抗氧化能力,增强抗凋亡基因表达来增强运动能力。间歇训练后,快慢肌应对细胞内Ca2 升高的能力增强,这可能是间歇训练增强运动能力的另一细胞内信息转导机制。     

Protective Role of Catechin on <Emphasis Type="SmallCaps">d</Emphasis>-Galactosamine Induced Hepatotoxicity Through a p53 Dependent Pathway

Objective of this study was to obtain a better understanding of the mechanism responsible for the d-galactosamine (d-GalN) induced hepatotoxicity and to study the effect of catechin against d-GalN induced hepatotoxicity. Catechin 50 and 100 mg/kg b.wt was administered for 1 week by oral route. Liver damage was induced by intra-peritoneal administration of 400 mg/kg b.wt d-galactosamine on the last day of catechin treatment. At the end of treatment all animals were killed and liver enzyme levels were estimated. Dissected hepatic samples were used for histopathology, RNA isolation, expression studies of Bax, Bcl-2 and p53 mRNA levels and mitochondrial membrane potential studies. We found that increases in the liver enzyme activity and decrease in antioxidant enzyme activity by d-GalN were significantly restricted by oral pretreatment with catechin. Disruption of mitochondrial membrane potential, up regulation of p53, Bax and down regulation of Bcl-2 mRNA levels in the liver of d-GalN intoxicated rats were effectively prevented by pretreatment with catechin.     

Bcl-2、Bax和Caspase-8在大运动量大鼠心肌组织中表达及壳寡糖的干预作用

目的:研究Bcl-2、Bax和Caspase-8mRNA在大运动量大鼠心肌组织中表达变化及壳寡糖的调节作用.方法:用健康3月龄SPF级SD雄性大鼠48只,按体重完全随机设计分为正常对照组、运动组、阳性对照组和壳寡糖组.运动组、阳性对照组和壳寡糖组进行为期6周的跑台训练.训练结束24h后处死大鼠,迅速取出心脏,运用荧光实时定量PCR技术检测心肌组织Bcl-2、Bax和Caspase-8mRNA表达水平;同时利用透射电镜观察大鼠心肌组织形态结构.结果:运动组Bcl-2mRNA的表达水平显著降低,而Bax和Caspase-8 mRNA的表达水平显著增高,与其他3组比较呈显著差异(P＜0.05).壳寡糖组Bcl-2、Bax和Caspase-8 mRNA的表达水平与阳性对照组和正常对照组比较差异无显著性(P＞0.05).电镜观察,运动组心肌组织可见凋亡细胞,心肌细胞损伤明显,肌原纤维模糊、断裂甚至坏死,线粒体肿胀等形态学改变.壳寡糖组与阳性对照组和正常对照组比较心肌组织形态结构无明显变化.结论:大运动量训练能导致大鼠心肌组织的基因表达异常,造成心肌组织损伤.壳寡糖可调节大运动量训练大鼠心肌组织Bcl-2、Box和Caspase-8mRNA表达水平,维持心肌组织的正常形态结构.     

甘草黄酮对大强度耐力运动大鼠肾脏组织细胞凋亡及Bax、Bcl-2蛋白表达的影响

目的:探讨甘草黄酮对大强度耐力运动大鼠肾脏组织细胞凋亡及Bax(促凋亡基因,B apoptosis cell matrixgene)、Bcl-2(B细胞淋巴瘤基因-2,B cell lymphoma gene-2)蛋白表达的影响。方法选取SD雄性健康大鼠24只,随机分为安静组、大强度运动组和运动加药组;采用跑台训练6周后取材,应用免疫组织化学法测检测各组大鼠肾脏组织细胞凋亡及Bax和Bcl-2蛋白表达的变化。结果:与安静对照组相比,大强度耐力运动组和运动加药组大鼠细胞凋亡指数AI均有不同程度增加;大强度运动组Bax、Bcl-2蛋白表达(MOD)均呈非常显著差异性(P<0.01),运动加药组Bax蛋白表达(MOD)均呈非常显著差异性(P<0.01);运动加药组Bcl-2蛋白表达(MOD)与大强度运动组具有非常显著差异性(P<0.01);大强度运动组和运动加药组Bax/Bcl-2比值分布呈不同程度的显著差异性(P<0.05,P<0.01)。结论:甘草黄酮能够提高大强度运动大鼠抗氧化能力,降低肾脏组织自由基的产生,抑制肾脏组织细胞的凋亡。     

甘草黄酮对大强度耐力运动大鼠肾脏组织Ca~(2+)、Mg~(2+)-ATPase及Bax、Bcl-2蛋白表达的影响

目的:探讨甘草黄酮对大强度耐力运动大鼠肾脏组织Ca2+、Mg2+-ATPase及Bax、Bcl-2表达的影响。方法:选取雄性健康SD大鼠24只,随机分为安静组、大强度运动组和运动加药组,采用跑台训练6周后取材,检测各组大鼠肾脏组织Ca2+、Mg2+-ATPase活性及Bax和Bcl-2表达的变化。结果:与安静对照组相比,大强度运动组和运动加药组肾脏组织Ca2+、Mg2+-ATPase活性均呈非常显著性下降(P0.01);其中运动加药组Ca2+、Mg2+-TPase活性较大强度运动组均具有非常显著差异性提高(P0.01);大强度耐力运动组和运动加药组大鼠细胞凋亡指数AI均有不同程度增加;大强度运动组Bax、Bcl-2蛋白表达(MOD)均呈非常显著差异性(P0.01),运动加药组Bax蛋白表达(MOD)均呈非常显著差异性(P0.01);运动加药组Bcl-2蛋白表达(MOD)与大强度运动组具有非常显著差异性(P0.01);大强度运动组和运动加药组Bax/Bcl-2比值分布呈不同程度的显著差异性(P0.05,P0.01)。结论:甘草黄酮能够增强大强度运动大鼠抗氧化能力,降低肾脏组织自由基的产生,抑制组织细胞的凋亡。     

Spinal cord decompression reduces rat neural cell apoptosis secondary to spinal cord injury

Objective: To determine whether spinal cord decompression plays a role in neural cell apoptosis after spinal cord injury. Study design: We used an animal model of compressive spinal cord injury with incomplete paraparesis to evaluate neural cell apoptosis after decompression. Apoptosis and cellular damage were assessed by staining with terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate nick-end labelling (TUNEL) and immunostaining for caspase-3, Bcl-2 and Bax. Methods: Experiments were conducted in male Spragne-Dawley rats (n=78) weighing 300-400 g. The spinal cord was compressed posteriorly at T10 level using a custom-made screw for 6 h, 24 h or continuously, followed by decompression by removal of the screw. The rats were sacrificed on Day 1 or 3 or in Week 1 or 4 post-decompression. The spinal cord was removed en bloc and examined at lesion site, rostral site and caudal site (7.5 mm away from the lesion). Results: The numbers of TUNEL-positive cells were significantly lower at the site of decompression on Day l, and also at the rostral and caudal sites between Day 3 and Week 4 post-decompression, compared with the persistently compressed group. The numbers of cells between Day 1 and Week 4 were immunoreactive to caspase-3 and B-cell lymphoma-2 (Bcl-2)-associated X-protein (Bax), but not to Bcl-2, correlated with those of TUNEL-positive cells. Conclusion: Our results suggest that decompression reduces neural cell apoptosis following spinal cord injury.