人参皂甙Rd对匹罗卡品致癎大鼠模型中netrin-1表达及神经元凋亡的影响

目的探讨人参皂甙Rd(GSRd)对大鼠癫癎持续状态后齿状回netrin-1表达及海马神经元凋亡的影响。方法健康Wistar大鼠30只,随机分为颞叶癫癎组、GSRd组和对照组,每组10只。氯化锂-匹罗卡品建立大鼠颞叶癫癎模型,采用免疫组织化学法及TUNEL法观察颞叶癫癎组、GSRd组和对照组齿状回netrin-1蛋白表达及海马神经元凋亡细胞数情况。结果与对照组比较,颞叶癫癎组大鼠30 d齿状回netrin 1蛋白表达明显增高,海马CA3区TUNEL阳性细胞数在癫癎持续状态后7 d明显增高,差异有统计学意义(P<0.05);与颞叶癫癎组比较,GSRd组大鼠30 d齿状回nctrin l蛋白表达明显降低,海马CA3区TUNEL阳性细胞数在癫癎持续状态后7 d明显降低,差异有统计学意义(P<0.05)。结论 GSRd可能通过下调netrin 1的表达,并使神经元凋亡数目减少,从而发挥对神经元的保护作用。     

涟波振荡与大鼠颞叶癫癎发作关系的研究

目的探讨脑电中的涟波振荡与大鼠颞叶癫癎发作的关系。方法10只SD大鼠,在双侧齿状回和海马分别置入深部电极,用氯化锂-毛果芸香碱腹腔注射诱发大鼠颞叶癫癎,记录癫癎发作前后的深部脑电(采样频率10KHz,低通为5000Hz)。用小波变换提取脑电中的涟波和快速涟波成分,并用能量法对癫癎发作前后的涟波成分进行分析。结果涟波和快速涟波的能量变化与癫癎发作的状态十分符合。癫癎发作时,快速涟波和涟波的能量都有明显增加,累积速率大。给予地西泮后,两者的能量都有所减小,累积速率趋于稳定,但快速涟波的能量累积速度降低得更快。结论脑电中的涟波振荡成分对癫癎发作有指示性作用。     

癫痫大鼠海马线粒体COXⅠ和COXⅣ表达的变化

目的探讨癫痫对大鼠海马线粒体细胞色素氧化酶（COX）的mtDNA和nDNA编码亚基Ⅰ、Ⅳ表达的影响。方法成年雄性Wistar大鼠随机分为生理盐水对照组、癫痫持续状态（SE）后急性期（3h）、静止期（7d）、慢性期（45d）组和注射匹鲁卡品（PILO）但未出现SE组。免疫组化并荧光实时定量PCR检测海马线粒体COXⅠ、Ⅳ阳性染色及其mRNA的表达。结果COXⅠ阳性细胞数在SE后3h明显增加,7d降到对照组水平,45d显著降低;COXⅣ阳性细胞数SE后3h稍有增加,但较对照组无显著性差异,7和45d时COXⅣ染色变化与对照组相似;注射PILO但未出现SE组COXⅠ、Ⅳ的表达与对照组类似。COXⅠmRNA在SE后3h表达明显升高（P〈0.001）,7d时降到对照水平,45d显著降低（P〈0.001）;COXⅣmRNA在3h时表达较对照组升高,但差异无显著性,7和45d时下降至对照组水平。注射PILO但无SE组与对照组结果类似。结论颞叶癫痫海马COX功能紊乱与痫性发作相关,线粒体编码的基因更易受痫性发作的影响。     

磷酸二酯酶5抑制剂促进大鼠脑缺血再灌注后神经及血管再生的研究

目的探讨磷酸二酯酶5抑制剂西地那非对大鼠脑缺血再灌注后海马神经前体细胞标记物微管相关蛋白增殖及血管内皮细胞生长因子(VEGF)表达的影响。方法雄性SD大鼠75只,随机分为假手术组5只,局灶性脑缺血再灌注组(单纯缺血组)35只及局灶性脑缺血+西地那非组(西地那非组)35只。西地那非组在大脑中动脉局灶缺血模型再灌注后2 h喂服西地那非3 d。单纯缺血组和西地那非组在术后2 h、1 d、3 d、5 d、7 d、10 d和14 d检测神经功能缺损评分。免疫组织化学方法检测各时间点海马神经前体细胞标记物微管相关蛋白阳性细胞及梗死灶周围VEGF的吸光度值。结果假手术组几乎无微管相关蛋白表达。与单纯缺血组比较,西地那非组7 d、10 d、14 d神经功能缺损评分明显升高,差异有统计学意义(P<0.05);西地那非组5 d、7 d、10 d、14 d微管相关蛋白明显高于单纯缺血组,差异有统计学意义(P<0.05,P<0.01);西地那非组3 d、5 d、7 d、10 d VEGF明显高于单纯缺血组,差异有统计学意义(P<0.05,P<0.01)。结论西地那非能够促进大鼠脑缺血再灌注后急性期神经及血管再生,改善神经功能。     

快速眼动睡眠剥夺诱导大鼠皮质和海马及延髓caspase-12的表达

目的观察不同时间快速眼动睡眠剥夺(SD)对大鼠皮质、海马及延髓内质网凋亡因子caspase-12的表达影响。方法将80只雄性Wistar大鼠分为SD组(40只)、SD后恢复睡眠组(RS组,20只)、对照组(20只);其中SD组又分为SD1、3、5、7天亚组,RS组又分为RS6、12h亚组;对照组又分为实验环境对照组(TC组)和正常睡眠对照组(CC组)。采用改良多平台SD法、免疫组织化学法、Western blot及RT-PCR检测脑组织中caspase-12表达分布规律及时空变化;TUNEL法检测凋亡细胞分布。结果RT-PCR检测大鼠快速眼动SD1天caspase-12有表达并呈逐渐上升趋势,7天达高峰,RS6、12h及TC组和CC组无caspase-12表达。免疫组织化学及Western blot检测发现,SD1、3天激活的caspase-12表达增加(P<0.05),5、7天及RS组、TC组和CC组无激活的caspase-12表达。上述变化海马区最明显,皮质区次之,延髓区无改变。TUNEL检测SD1、3天凋亡细胞海马区最多(P<0.05),皮质和延髓区次之。结论SD启动了内质网凋亡通路,并随SD的终止而终止。SD可能是造成脑组织损害的机制之一,海马区对SD导致的脑损害最敏感。     

大鼠缺氧缺血后海马神经元凋亡及凋亡抑制蛋白XIAP表达的变化

目的 探讨新生大鼠缺氧缺血性脑损伤(HIBD)后海马CA1区神经元凋亡及X连锁凋亡抑制蛋白(XIAP)表达的变化规律.方法选择48例新生Wistar大鼠为HIBD组,并选择12只新生大鼠分为假手术组(n=6)和正常对照组(n=6).HIBD制模后3h、6h、12h、24 h、48 h、72 h、7 d、14 d处死取材,每次处死6只,采用流式细胞技术检测3组大鼠海马神经元的凋亡率,并应用免疫组织化学染色方法检测各组海马CA1区XIAP的表达变化情况.结果 与假手术组相比,HIBD组缺氧缺血后3h海马神经元凋亡率即开始升高,但差异无统计学意义(P＞0.05);于缺氧缺血后12h凋亡率显著升高(P＜0.05),48 h时达高峰,72 h时开始下降,7d时明显低于高峰水平(P＜0.05),而与假手术组无显著差异,14 d时基本恢复至假手术组水平.正常对照组和假手术组海马CA1区有极少量XIAP阳性表达细胞.HIBD组于缺氧缺血3h时XIAP阳性表达显著升高(P＜0.05),之后逐渐升高,在48 h时达到高峰,72 h时开始逐渐下降,7d时已明显低于高峰水平(P＜0.05),但仍明显高于正常对照组和假手术组水平,在14 d时略高于正常对照组和假手术组,但差异无统计学意义(P＞0.05).XIAP蛋白表达与HIBD后各时间点阳性凋亡细胞出现呈负相关(r=-0.564,P＜0.05).结论 XIAP蛋白的过度表达在脑缺氧缺血后细胞凋亡的调控过程中起着重要作用,对HIBD损伤的脑神经细胞具有保护作用.     

法舒地尔对蛛网膜下腔出血大鼠铁死亡的影响

目的 探索法舒地尔(Fasudil)对蛛网膜下腔出血(subarachnoid hemorrhage, SAH)大鼠铁死亡的影响。方法24只SD大鼠按随机数字表法分为假手术组(Sham组,n=8)、SAH组(n=8)、SAH+Fasudil组(Fasudil组,n=8)。颈内动脉刺破法造SAH模型。Fasudil组造模后腹腔注射Fasudil(10 mg/kg 1次/12 h)。造模成功24 h后观察大鼠神经功能(Garcia JH评分及穿梭箱试验),检测脑组织Fe²⁺浓度,免疫组织化学染色、Western blot检测谷胱甘肽过氧化物酶4(GPX4)及长链脂酰辅酶A合成酶4(ACSL4)蛋白的表达。结果 与Sham组比较,SAH组大鼠Garcia JH评分显著降低,海马区脑组织中Fe²⁺含量显著增高,GPX4表达明显减少,ACSL4蛋白表达明显增高,差异有统计学意义(P<0.05)。与SAH组比较,Fasudil组大鼠Garcia JH评分增高[(13.88±3.94)分vs(10.13±4.39)分,P<0.05],海马区脑组...     

左乙拉西坦对癫痫大鼠海马组织中5-HT2A受体表达及其认知功能的影响

目的探讨左乙拉西坦(LEV)对癫痫大鼠海马组织中5-羟色胺2A(5-HT2A)受体动态表达及对认知功能的影响。方法 108只Wistar大鼠随机分为对照组(NS)24只、正常给药组(LEV)24只、癫痫模型组(Li-PILO)30只、癫痫给药组(Li-PILO+LEV)30只,分别给予LEV组和Li-PILD+LEV组大鼠LEV 200 mg/kg 1次/d灌胃,连续28 d。采用RT-PCR方法分别在第7、14、28天动态检测大鼠海马组织中5-HT2A受体的表达,Morris水迷宫实验测试大鼠的空间学习记忆。结果 LEV与NS组5-HT2A受体表达水平比较差异无统计学意义(P0.05);与NS组比较,LiPILO组在第7天时表达水平降低,且随时间延长降低水平越明显,即在第14、28天5-HT2A受体表达水平明显降低(P0.05);与Li-PILO型组比较,Li-PILO+LEV组5-HT2A受体在第7、14、28天表达水平明显升高(P0.05)。与Li-PILO组比较,Li-PILO+LEV组的逃避潜伏期明显缩短、穿越平台次数显著增加(均P0.05)。结论 LEV的抗癫痫作用可能与通过上调5HT-2A受体的表达有关,其在抗癫痫的同时还可以改善大鼠的空间学习记忆。     

依托咪酯在大鼠最大电休克和戊四氮模型中的抗惊厥作用

目的研究依托咪酯在最大电休克(maximal electroshock seizure,MES)和戊四氮(metrazol seizure test,MST)惊厥实验中的抗惊厥作用。方法复制160只Wistar大鼠MES和MST模型,MES实验大鼠80只随机分为4组,分别为依托咪酯10 mg/kg组(E10组)、5 mg/kg组(E5组)、2.5 mg/kg组(E2.5组)和对照1组,每组20只。MST实验大鼠80只随机分为4组,分别为依托咪酯10 mg/kg组(E10组)、5 mg/kg组(E5组)、2.5 mg/kg组(E2.5组)和对照2组,每组20只。观察MES中大鼠的惊厥发生率、死亡率和强直持续期,MST中惊厥潜伏期、惊厥数和死亡数,并记录每只大鼠的发作强度。发作24 h后,灌注固定后取脑,常规HE染色及Nissl染色。结果在MES中,与对照1组比较,E2.5组可缩短强直持续期(P<0.05),对惊厥发生率无明显影响,E5组可同时缩短强直持续期(P<0.01)降低惊厥发生率,E10组可完全拮抗大鼠电惊厥的发生。在MST中,与对照2组比较,依托咪酯各组仍具明显抗惊厥作用,其抗惊厥作用具有剂量依赖性,用量越大,大鼠惊厥发生强度越小。结论依托咪酯在动物模型观察中,具有对抗癫癎发作的作用,有希望成为临床治疗癫癎发作的药物。     

17β-雌二醇抑制血管球囊损伤后血管外膜增殖

目的观察17β-雌二醇对血管球囊损伤后外膜增殖的影响。方法去卵巢颈动脉球囊损伤兔模型随机分为17β-雌二醇组(20μg.kg-1.d-1)和溶剂组(棉花油),每组25只,并分别在球囊损伤术后1、3、7、14、28天处死兔,处死前18 h和12 h给予5溴-2脱氧尿苷标记增殖的细胞,应用免疫组织化学的方法检测增殖的细胞,计算机图像分析系统测定外膜厚度并计数阳性细胞。结果溶剂组血管球囊损伤后3~7天,血管外膜明显增殖(P<0.05);与溶剂组比较,17β-雌二醇组外膜厚度明显变薄(15%,P<0.05),外膜增殖细胞数明显减少(45%,P<0.05)。结论17β-雌二醇可明显抑制兔颈动脉球囊损伤后外膜的增殖。     

Melatonin treatment mimics the antidepressant action in chronic corticosterone‐treated mice

Abstract: Melatonin, involved in circadian cycle, provides protective effects on neuronal cells and acts as antidepressant by restoration of corticosterone levels. A mouse model of anxiety/depressive‐like behavior, induced by chronic corticosterone treatment, has been used to evaluate behavior and adult hippocampal neurogenesis in mice and their possible modulation under melatonin. With this aim, CD1 mice were subjected to 7 wk of corticosterone administration, and then behavioral tests as novelty‐suppressed feeding, open field and a forced swim test were performed. Cell proliferation in hippocampal dentate gyrus (DG) was investigated by 5‐bromo‐2′‐deoxyuridine and doublecortin immunohistochemistry techniques, and stereological procedure was used to quantify labeled cells. Golgi‐impregnated method was used to evaluate the changes of dendritic spines in DG neurons. A new therapeutic approach with antidepressant‐like substances (3 wk) such as melatonin (8 mg/kg) was employed to possibly modulate neural development in the adult hippocampus and the behavioral changes. The depressive‐like state caused by chronic corticosterone treatment was reversed by exogenous administration of melatonin; the proliferation of progenitor cells in mice hippocampus was significantly reduced under chronic corticosterone treatment (cort? 83.7 ± 20.3 versus cort+ 60.5 ± 18.2; P < 0.05), whereas long‐term treatment with melatonin prevented the corticosterone‐induced reduction in hippocampal cell proliferation (cort? 60.5 ± 18.2 versus mel 133.4 ± 26.9; P < 0.05). Corticosterone‐treated mice exhibited a reduced spine density, which was ameliorated by melatonin administration. These findings suggest a strong correspondence between behavior and neurogenesis, strengthening the hypothesis that neurogenesis contributes to the effects of melatonin as an antidepressant.     

离子型谷氨酸受体拮抗剂对大鼠脑缺血再灌注后海马齿状回5-溴脱氧尿核苷表达的影响

目的　观察选择性离子型谷氨酸受体 (iGluRs)拮抗剂对大鼠全脑缺血再灌注损伤后齿状回神经发生的调控作用 ,探讨谷氨酸 离子型谷氨酸受体通路在神经发生中的作用。方法　采用 5 溴脱氧尿核苷 (BrdU)标记分裂细胞 ,比较大鼠全脑缺血再灌注损伤后 7d和 14d时各iGluRs拮抗剂处理组与相应对照组之间海马齿状回神经前体细胞的增殖速度。结果　腹腔注射N 甲基 D 天门冬氨酸 (NMDA)受体阻滞剂 5 甲基二氢二苯丙环庚烯亚胺后显著抑制了大鼠全脑缺血后 7d和 14d时齿状回神经发生水平的升高 ,BrdU免疫阳性细胞数较缺血再灌注 +生理盐水组各时间点明显减少 ;而α 氨基羟甲基恶唑丙酸和 (或 )红藻氨酸受体阻滞剂二硝基喹喔啉对全脑缺血后不同时间点齿状回神经发生的增强基本没有影响。结论　全脑缺血再灌注损伤后NMDA受体通路的激活可能促进了齿状回神经发生。     

Melatonin pretreatment enhances the therapeutic effects of exogenous mitochondria against hepatic ischemia–reperfusion injury in rats through suppression of mitochondrial permeability transition

We tested the hypothesis that melatonin (Mel) enhances exogenous mitochondria (Mito) treatment against rodent hepatic ischemia–reperfusion (IR) injury. In vitro study utilized three groups of hepatocytes (i.e. nontreatment, menadione, and menadione–melatonin treatment, 4.0 × 10⁵ each), while in vivo study used adult male Sprague Dawley rats (n = 40) equally divided into sham‐control (SC), IR (60‐min left‐lobe ischemia + 72‐hr reperfusion), IR‐Mel (melatonin at 30 min/6/8 hr after reperfusion), IR‐Mito (mitochondria 15,000 μg/rat 30 min after reperfusion), and IR‐Mel‐Mito. Following menadione treatment in vitro, oxidative stress (NOX‐1/NOX‐2/oxidized protein), apoptotic (cleaved caspase‐3/PARP), DNA damage (γ‐H2AX/CD90/XRCC1), mitochondria damage (cytosolic cytochrome c) biomarkers, and mitochondrial permeability transition were found to be lower, whereas mitochondrial cytochrome c were found to be higher in hepatocytes with melatonin treatment compared to those without (all P < 0.001). In vivo study demonstrated highest liver injury score and serum AST in IR group, but lowest in SC group and higher in IR‐Mito group than that in groups IR‐Mel and IR‐Mel‐Mito, and higher in IR‐Mel group than that in IR‐Mel‐Mito group after 72‐hr reperfusion (all P < 0.003). Protein expressions of inflammatory (TNF‐α/NF‐κB/IL‐1β/MMP‐9), oxidative stress (NOX‐1/NOX‐2/oxidized protein), apoptotic (caspase‐3/PARP/Bax), and mitochondria damage (cytosolic cytochrome c) biomarkers displayed an identical pattern, whereas mitochondria integrity marker (mitochondrial cytochrome c) showed an opposite pattern compared to that of liver injury score (all P < 0.001) among five groups. Microscopically, expressions of apoptotic nuclei, inflammatory (MPO ⁺ /CD68 ⁺ /CD14 ⁺ cells), and DNA damage (γ‐H2AX ⁺ cells) biomarkers exhibited an identical pattern compared to that of liver injury score (all P < 0.001) among five groups. Melatonin‐supported mitochondria treatment offered an additional benefit of alleviating hepatic IR injury.     

mTOR信号介导的自噬在褪黑素减轻心脏缺血/再灌注损伤中的作用

目的 探讨mTOR信号介导的自噬在褪黑素（melatonin,Mel）减轻心脏缺血/再灌注损伤中的作用。方法 将60只8周龄C57BL/6小鼠随机分为假手术（Sham）组、单纯褪黑素10 mg/(kg·d)处理(Mel)组、缺血/再灌注（ischemia reperfusion,I/R）组和褪黑素10 mg/(kg·d)干预I/R（Mel+I/R）组。采用冠状动脉左前降支结扎术制备心肌I/R模型,HE染色观察心肌组织形态学变化,试剂盒检测各组血清中LDH的含量,TUNEL染色检测各组细胞凋亡情况,蛋白印迹法（Western blot）检测自噬相关蛋白微管相关蛋白1轻链3（microtubule-associated protein 1 light chain 3,LC3）I和II、Beclin1和mTOR磷酸化的表达,免疫荧光染色法检测LC3B的表达。结果 与Sham组相比,Mel组各项指标均无明显变化;I/R组心肌纤维断裂明显排列紊乱,血清中LDH含量明显增加（P<0.01）,TUNEL阳性细胞明显增多（P<0.01）,LC3II和Beclin1表达显著升高（P<0.01）,而磷酸化mTOR的表达降低（P<0.01）,免疫荧光结果显示LC3B表达增加（P<0.01）; Mel+I/R组可明显减轻心肌纤维的断裂,降低血清中LDH含量（P<0.01）,减少TUNEL阳性细胞数（P<0.01）,减少LC3II和Beclin1的表达（P<0.01）,降低免疫荧光染色中LC3B的表达（P<0.01）。结论 褪黑素通过调节mTOR信号介导的自噬减轻心脏I/R损伤。     

Maternal melatonin stimulates growth and prevents maturation of the capuchin monkey fetal adrenal gland

The primate fetal adrenal reaches a large size relative to body weight followed by a rapid decrease in size in the postnatal period. We tested the hypothesis that maternal melatonin stimulates growth and prevents maturation of the primate fetal adrenal gland. We suppressed maternal melatonin by exposing eight pregnant capuchin monkeys to constant light (LL) from 63% to 90% gestation (term 155 days). Three of these received daily oral melatonin replacement (LL + Mel). Five mothers remaining in light:dark cycle were used as controls. Fetuses were delivered at 90% gestation. The absence of maternal melatonin selectively decreased fetal adrenal weight (Control: 488.8 +/- 51.5; LL: 363.2 +/- 27.7 and LL + Mel 519 +/- 46 mg; P < 0.05 ANOVA) without effecting fetal weight, placental weight or the weight of other fetal tissues. Changes in fetal adrenal size were accompanied by an increase in the levels of Delta5-3beta-hydroxysteroid dehydrogenase (3beta-HSD) mRNA (Control: 0.8 +/- 0.2; LL: 5.2 +/- 0.6 and LL + Mel 0.8 +/- 0.1; 3beta-HSD/18S-rRNA; P < 0.05 ANOVA). In vitro we found that maternal melatonin suppression increased basal progesterone production to levels similar to those of the adult adrenal gland (Control: 0.36 +/- 0.09; LL 0.99 +/- 0.13; LL + Mel 0.18 +/- 0.06 and adult: 0.88 +/- 0.10 ng/mg of tissue; P < 0.05 ANOVA) but no change in cortisol production. We found an increased production of cortisone (Control: 1.65 +/- 0.60; LL: 5.44 +/- 0.63; LL + Mel: 2.90 +/- 0.38 and adult: 1.70 +/- 0.45 ng/mg of tissue; P < 0.05 ANOVA). Collectively, the effects of maternal melatonin suppression and their reversion by maternal melatonin replacement suggest that maternal melatonin stimulates growth and prevents maturation of the capuchin monkey fetal adrenal gland.     

褪黑素减轻心肌缺血/再灌注损伤的作用及机制

目的:探讨褪黑素（melatonin,Mel）在大鼠心肌缺血/再灌注（MI/R）损伤中的拮抗作用及其机制。方法:80只体质量200~250 g雄性SD大鼠随机分为4组:假手术（Sham）组、溶剂对照（MI/R+V）组、Mel治疗（MI/R+Mel）组、Mel+EX527（MI/R+Mel+EX）组。常规结扎左冠状动脉前降支行心肌缺血/再灌注手术,缺血30 min,再灌72 h后超声心动图法检测各组大鼠心功能,再灌6 h后ELISA法检测血清酶学指标,TUNEL法检测心肌细胞凋亡率,Evans blue-TTC双染法测定梗死面积,Western blot法检测沉默信息转录调控因子1（SIRT1）、乙酰化叉头转录因子1（Ac-Foxo1）及凋亡相关蛋白表达水平。结果:Mel治疗可显著改善MI/R损伤后心功能,降低血清肌酸激酶（CK）及乳酸脱氢酶（LDH）水平,降低凋亡率及梗死面积,上调SIRT1表达,下调Ac-Foxo1水平,降低凋亡相关蛋白表达。而使用EX527阻断SIRT1信号后逆转Mel的上述作用（均P<0.01）。结论:Mel可发挥抗凋亡作用减轻MI/R损伤并改善心功能,其作用机制可能与其激活SIRT1信号通路并降低Ac-Foxo1水平有关。     

褪黑素通过激活Akt信号通路缓解高糖诱发的原代心肌细胞损伤

目的 明确高糖对心肌细胞损伤的影响;揭示褪黑素（Mel）在高糖诱发乳鼠原代心室肌细胞损伤中的作用及机制。 方法 体外培养乳鼠原代心室肌细胞,分为4组:正常葡萄糖浓度组(NG)、高糖组(HG,HG=25 mmo/L)、高糖+褪黑素组（HG+Mel,HG=25 mmo/L;Mel=30 μmo/L）、高糖+褪黑素+ PI3K/Akt抑制剂组（HG+Mel,HG=25 mmo/L;Mel=30 μmo/L;LY294002=50 μmo/L）组,采用Western Blotting、RT-PCR和免疫荧光技术检测心肌细胞凋亡相关蛋白以及PI3K/p-Akt等指标,评价褪黑素对高糖诱发心肌细胞凋亡的作用及机制。 结果 与NG组比较,HG组心肌细胞Cl -Caspase3、Caspase9的mRNA及蛋白表达明显升高,伴有p-Akt的mRNA及蛋白表达降低和PI3K蛋白表达降低;与HG组相比,HG+Mel组心肌细胞Cl-Caspase3、Caspase9的mRNA及蛋白表达下调伴有p-Akt的mRNA及蛋白表达回升和PI3K蛋白表达升高;与HG+Mel组相比,HG+Mel+LY294002组心肌细胞的Cl-Caspase3、Caspase9的mRNA及蛋白表达上升伴有p-Akt蛋白表达水平显著降低和PI3K蛋白表达降低。免疫荧光的结果与Western Blotting、RT-PCR的结果趋势一致。 结论 褪黑素通过激活PI3K/Akt信号通路缓解高糖诱导的原代心肌细胞损伤。     

Effect of melatonin on apoptosis, proliferation and differentiation of urothelial cells after cyclophosphamide treatment

Abstract:  Melatonin was recently shown to have protective effects against cyclophosphamide (CP)-induced hemorrhagic cystitis (HC) by diminishing bladder oxidative stress. HC is accompanied by destruction of the bladder urothelium and followed by apoptosis and rapid regeneration via proliferation and differentiation of urothelial cells, reaching complete restoration of normal urothelium in three weeks. Therefore, the effect of melatonin on apoptosis, proliferation and differentiation of urothelial cells, during destruction and regeneration of the urothelium three-weeks after a single dose CP treatment, was studied. F344 male rats were injected intraperitoneally with saline (control group) or melatonin (Mel group) or a single dose of CP (100 mg/kg; CP group) or melatonin (10 mg/kg) with CP (Mel + CP group). Melatonin co-treatment with CP significantly reduced apoptosis and increased proliferation of urothelial cells at day 1 and thus prevented extensive loss of cells from the urothelium. However, proliferation indices at days 4 and 7 after melatonin and CP co-treatment suddenly dropped and therefore the development of hyperplasia was prevented. Melatonin co-treatment with CP also resulted in earlier differentiation of superficial urothelial cells. Melatonin seems to have protective effect against CP-induced urothelial damage and a favorable impact on regeneration and restoration of normal urothelium, since it reduces the number of apoptotic and proliferating urothelial cells and results in their earlier differentiation.