Neuroprotective effect of the antiparkinsonian drug pramipexole against nigrostriatal dopaminergic degeneration in rotenone-treated mice

Pramipexole, an agonist for dopamine (DA) D2/D3-receptors, has been used to treat both early and advanced Parkinson's disease (PD). In this study, we examined the effect of pramipexole on DA neurons in a PD model of C57BL/6 mice, which were treated with rotenone (30 mg/kg, p.o.) daily for 28 days. Pramipexole (1 mg/kg, i.p.) was injected daily 30 min before each oral administration of rotenone. Chronic oral administration of rotenone caused a loss of DA neurons in the substantia nigra pars compacta (SNpc), motor deficits and the up-regulation of α-synuclein immunoreactivity in some surviving DA neurons. Pramipexole inhibited rotenone-induced DA neuronal death and motor deficits, and reduced immunoreactivity for α-synuclein. In addition, pramipexole inhibited the in vitro oligomerization of human wild-type α-synuclein by H₂O₂ plus cytochrome c. To examine the neuroprotective effect of pramipexole against oxidative stress, we used a DJ-1-knockdown SH-SY5Y cell line and electron spin resonance (ESR) spectrometry. Simultaneous treatment with H₂O₂ and pramipexole resulted in the significant protection of DJ-1-knockdown cells against cell death in a concentration-dependent manner. A high concentration of pramipexole directly scavenged hydroxyl radical (OH) generated from H₂O₂ and Fe²⁺. Furthermore, pramipexole increased Bcl-2 immunoreactivity in DA neurons in the SNpc. These results suggest that pramipexole may protect DA neurons against exposure to rotenone by chronic oral administration, and this effect is mediated by multiple functions including scavenging of OH and induction of Bcl-2 protein.     

阿托伐他汀钙对帕金森病细胞模型的保护作用及其临床意义

目的:评价阿托伐他汀钙对帕金森病细胞模型及帕金森病患者临床症状的影响。方法:首先使用MPP+处理SH-SY5Y细胞建立帕金森病细胞模型。观察阿托伐他汀钙在该模型中对Wnt通路以及细胞凋亡的影响。其次选取66例符合纳入标准的临床患者,其中33例服用多巴丝肼片和盐酸普拉克索(普通治疗组)。其余33例则因其他原因在使用多巴丝肼片和盐酸普拉克索治疗期间服用阿托伐他汀钙片(阿托伐他汀组)。观察两组患者的Hoehn-Yahr分级,UPDRS评分,以及不良反应的发生率。结果:在MPP+处理组,Wnt通路受到抑制且细胞发生凋亡,而阿托伐他汀钙预处理可缓解MPP+引起的Wnt通路的抑制和细胞凋亡,差异具有统计学意义(P0.05)。治疗8周后阿托伐他汀组的Hoehn-Yahr分级改善情况显著优于普通治疗组的改善情况,并且差异具有统计学意义(P0.05);治疗8周后普通治疗组的UPDRS评分高于阿托伐他汀组的评分,差异具有统计学意义(P0.05);阿托伐他汀组的不良反应发生率低于普通治疗组,但差异无统计学意义(P0.05)。结论:阿托伐他汀钙可通过Wnt通路保护MPP+引起的细胞凋亡并且在临床治疗中能较好的改善帕金森病患者的运动和非运动症状。     

Determination of pramipexole (U-98,528) in human plasma and urine by high-performance liquid chromatography with electrochemical and ultraviolet detection

A sensitive and selective high-performance liquid chromatographic (HPLC) method was developed for the determination of pramipexole in human plasma and urine. Plasma/urine is made alkaline before pramipexole and BHT-920 (internal standard) are extracted by ethyl ether and back-extracted with a solution that contains heptanesulfonic acid. Separation is achieved by ion-pair chromatography on a Zorbax Rx C₈ column with electrochemical detection at 0.6 V for plasma and ultraviolet detection at 286 nm for urine. The retention times of pramipexole and internal standard are approximately 14.4 and 10.7 min, respectively. The assay is linear in concentration ranges of 50 to 15 000 pg/ml (plasma) and 10 to 10 000 ng/ml (urine). The correlation coefficients are greater than 0.9992 for all curves. For the plasma method, the analysis of pooled quality controls (300, 3000, and 10 000 pg/ml) demonstrates excellent precision with relative standard deviations (R.S.D.) (n=18) of 1.1%, 2.3%, and 6.8%, respectively. For the urine method, quality control pools prepared at 30, 300, and 3000 ng/ml had R.S.D. values (n=18) of 2.9%, 1.7%, and 3.0%, respectively. The plasma and urine controls were stable for more than nine and three months, respectively. The mean recoveries for pramipexole and internal standard from plasma were 97.7% and 98.2%, respectively. The mean recoveries for pramipexole and internal standard from urine were 89.8% and 95.1%, respectively. The method is accurate with all intra-day (n=6) and overall (n=18) mean values for the quality control samples being less than 6.4 and 5.8% from theoretical for plasma and urine, respectively.     

盐酸普拉克索联合美多巴对老年帕金森病的临床疗效及对运动功能的影响

目的:研究盐酸普拉克索联合美多巴对老年帕金森病的临床疗效及对运动功能的影响。方法:选择2014年3月~2015年8月在我院进行诊治的老年帕金森病患者210例,随机分为观察组和对照组,对照组给予美多巴,观察组给予盐酸普拉克索联合美多巴,比较两组的临床疗效,治疗前后运动功能、生活质量的变化情况和不良反应的发生情况。结果:观察组的治疗有效率为85.71%,明显高于对照组的65.71%(P0.05);治疗12周后,观察组UPDRS评分与治疗前和对照组相比均明显降低(P0.05);治疗12周后,观察组生理、心理、独立性、社会关系和环境等方面的评分与治疗前和对照组相比均明显升高(P0.05);两组间恶心、呕吐、开关现象、精神症状等不良反应发生率相比无明显差异(P0.05)。结论:盐酸普拉克索联合美多巴对老年帕金森病疗效显著,能明显改善运动功能,且用药安全,值得推广应用。     

Pramipexole Reduces Reactive Oxygen Species Production In Vivo and In Vitro and Inhibits the Mitochondrial Permeability Transition Produced by the Parkinsonian Neurotoxin Methylpyridinium Ion

Abstract: Sporadic Parkinson's disease is associated with a defect in the activity of complex I of the mitochondrial electron transport chain. This electron transport chain defect is transmitted through mitochondrial DNA, and when expressed in host cells leads to increased oxygen free radical production, increased antioxidant enzyme activities, and increased susceptibility to programmed cell death. Pramipexole, a chemically novel dopamine agonist used for the treatment of Parkinson's disease symptoms, possesses antioxidant activity and is neuroprotective toward substantia nigral dopamine neurons in hypoxic-ischemic and methamphetamine models. We found that pramipexole reduced the levels of oxygen radicals produced by methylpyridinium ion (MPP⁺) both when incubated with SH-SY5Y cells and when perfused into rat striatum. Pramipexole also exhibited a concentration-dependent inhibition of opening of the mitochondrial transition pore induced by calcium and phosphate or MPP⁺. These results suggest that pramipexole may be neuroprotective in Parkinson's disease by attenuating intracellular processes such as oxygen radical generation and the mitochondrial transition pore opening, which are associated with programmed cell death.     

Determination of pramipexole (U-98,528) in human plasma by high-performance liquid chromatography with atmospheric pressure chemical ionization tandem mass spectrometry

A highly sensitive and selective HPLC-MS-MS method was developed for the determination of pramipexole in human plasma. The analytes, pramipexole and BHT-920 (internal standard), were extracted from plasma at basic pH with methyl tert.-butyl ether (MTBE). MTBE was evaporated to dryness and reconstituted in 100 μl of (95:5) methanol-water. Chromatographic separation was achieved on a Zorbax SB-CN column with a mobile phase of (15:5:80) water-0.1 M ammonium acetate—methanol. The analytes were detected utilizing HPLC in conjunction with atmospheric pressure chemical ionization (APCI) tandem mass spectrometry (MSM). The assay was linear in the concentration ranges of 50 to 5000 pg/ml. The analysis of pooled quality controls (150, 750, and 3000 pg/ml) demonstrated excellent precision with relative standard deviations (R.S.D.) (n=18) of 7.2%, 5.3% and 5.2%, respectively. The method is accurate with all intra-day (n=6) and overall (n=18) mean values being less than 11.7% from theoretical.     

普拉克索联合补肾活血通络胶囊治疗老年帕金森病的临床疗效及对血清5-HT、BDNF、S-100β水平的影响

目的:分析普拉克索联合补肾活血通络胶囊治疗老年帕金森病的临床效果及对血清5-羟色胺(5-HT)、脑源性神经营养因子(BDNF)、S-100β水平的影响。方法:选择我院2014年12月~2016年12月收治的96例老年帕金森病患者,按随机数字表法分为对照组和研究组,每组48例。对照组采用普拉克索治疗,研究组基于对照组加以补肾活血通络胶囊治疗。观察并比较两组临床疗效指标统一帕金森病评分量表Ⅰ(unified parkinson’s disease rating scale,UPDRS)Ⅰ、UPDRSⅡ、UPDRSⅢ、UPDRSⅣ、总UPDRS,血清5-HT、BDNF、S-100β水平的变化及不良反应的发生情况。结果:治疗后,研究组总有效率为87.50%,显著高于对照组(64.58%,P<0.05)。两组治疗后的UPDRSⅠ、UPDRSⅡ、UPDRSⅢ、UPDRSⅣ、总UPDRS、血清S-100β水平均较治疗前显著下降,且研究组以上指标均明显低于对照组。两组治疗后的血清5-HT、BDNF水平均较治疗前明显上升,且研究组以上指标均明显高于对照组(P<0.05)。研究组不良反应发生率显著低于对照组(P<0.05)。结论:普拉克索联合补肾活血通络胶囊治疗治疗老年帕金森病的临床效果优于单用普拉克索,可能与其显著提高血清5-HT及BDNF表达并降低S-100β水平有关。     

普拉克索治疗帕金森病合并抑郁的系统评价

目的:评价普拉克索治疗帕金森病合并抑郁的疗效和安全性。方法:通过电子检索和手工检索,运用Cochrance协作网系统评价的方法对纳入所有应用普拉克索治疗帕金森病合并抑郁的随机对照试验(RCT)进行系统评价。结果:共检出5个RCT,其中3个(454例)符合纳入标准,三项研究随访时间为3-57个月。Meta分析结果显示:1)抑郁改善情况:3项研究随访结束后,应用量表进行评分,普拉克索治疗组抑郁症状改善率明显对照组,两组差异有统计学意义[RR=0.63,95%CI(0.48,0.83),P<0.001];2)UPDRS评分变化:2项研究在治疗末应用UPDRS进行评分,UPDRSⅢ和Ⅱ相对于基线评分,普拉克索组均较对照组明显下降,两组之间差别有统计学意义;3)不良反应:与普拉克索组相比,对照组中因药物不良反应而终止试验研究的病例增多,两组相比有统计学差异[RR=0.48,95%CI(0.34,0.69),p<0.0001]。结论:现有的临床研究证据表明,与对照组相比,普拉克索能够改善帕金森病伴发抑郁病人的抑郁症状,并减轻帕金森病的运动症状,提高病人日常生活活动能力,且安全性较高。但因研究样本局限性,尚需进行大样本长期...     

Pharmacological approaches to counter the toxicity of dopa

Summary Dopa and related catecholamines and their degradation products have been demonstrated to have neurotoxic potential in a number of cellular andin vivo experiments. Several mechanisms have been hypothesized to be involved including generation of prooxidant products that subsequently oxidize membrane lipids and exposed macromolecules. We have utilized a neuronal culture of cerebellar granule cells to study the toxicity of Dopa and the ability of various neuroprotective and antiparkinsonian compounds to offer protection therefrom. This model is apparently based on the ability of Dopa to non-enzymatically induce an oxidative injury to the neuronal cultures. Evidence for this arises from the equal neurotoxic potency of L- and D-Dopa in these cells and the ability of catalase, superoxide dismutase and glutathione to protect the neurons from this toxicity. Further, we found that the neuroprotective antioxidant, PNU-101033 is more effective and potent than vitamin E and deprenyl in this regard. Similarly the D2/D3 agonist, pramipexole is also capable of blocking Dopa toxicity in this model and this effect is independent of dopamine receptor affinity as both enantiomers are equally potent in this assay but disparate in receptor affinity. Also the protection by pramipexole is accompanied by the preservation of reduced glutathione. Thus, this activity seems to be a function of the oxidation potential of pramipexole and it's consequent antioxidant property. Potent antioxidants are effective blockers of Dopa toxicity. If the mechanisms involved in this toxicity have relevance to the progression of Parkinson's pathology in Dopa treated (or untreated) patients, these compounds have the potential to alter the course of the illness.     

多巴丝肼联合普拉克索治疗帕金森病的临床疗效

目的:探讨多巴丝肼联合普拉克索治疗帕金森病的临床疗效。方法:以入院病历号为编号,根据随机数字表,将106名帕金森病患者随机分成分两组,每组53例。治疗过程中,给予多巴丝肼片治疗的患者记为对照组(53例);给予多巴丝肼联合普拉克索治疗的患者记为观察组(53例)。连续治疗12周,观察两组患者总疗效、UPDRS评分、HAMD评分及不良反应,探讨其临床治疗价值。结果:1观察组总有效率明显高于对照组总有效率,差异有统计学意义(P0.05)。2与治疗前相比,治疗后两组UPDRS各项评分均明显改善(P0.05),且观察组UPDRS各项评分明显优于对照组(P0.05)。3与治疗前相比,治疗后两组HAMD评分均明显改善(P0.05),且观察组HAMD评分明显优于对照组(P0.05)。结论:多巴丝肼联合普拉克索治疗帕金森病疗效确切,安全可靠,值得临床推广应用。