High-performance liquid chromatography/tandem mass spectrometry assay for the determination of 1-methyl-4-phenyl pyridinium (MPP+) in brain tissue homogenates

Hows, Mark E. P.; Ashmeade, Tracey E; Billinton, Andrew; Perren, M.J.; Austin, Angela A; Virley, David; Organ, Andrew J.; Shah, Ajit J.

doi:10.1016/j.jneumeth.2004.02.011

Cited by 24 publications

(26 citation statements)

References 19 publications

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“…levels by LC-MS/MS was performed in MPTP and MPTP plus ghrelin mice killed 90 min after one i.p. injection of 20 mg/kg MPTP as described by Hows et al (2004a). Mitochondrial inhibition was determined by MPP ?…”

Section: Measurement Of Mptp Metabolismmentioning

confidence: 99%

Neuroprotective Effect of Ghrelin in the 1-Methyl-4-Phenyl-1,2,3,6-Tetrahydropyridine Mouse Model of Parkinson’s Disease by Blocking Microglial Activation

Moon¹,

Kim

Hwang³

et al. 2009

Neurotox Res

183

142

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Ghrelin is an endogenous ligand for growth hormone (GH) secretagogue receptor 1a (GHS-R1a) and is produced and released mainly from the stomach. It was recently demonstrated that ghrelin can function as a neuroprotective factor by inhibiting apoptotic pathways. 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) causes nigrostriatal dopaminergic neurotoxicity in rodents; previous studies suggest that activated microglia actively participate in the pathogenesis of Parkinson's disease (PD) neurodegeneration. However, the role of microglia in the neuroprotective properties of ghrelin is still unknown. Here we show that, in the mouse MPTP PD model generated by an acute regimen of MPTP administration, systemic administration of ghrelin significantly attenuates the loss of substantia nigra pars compacta (SNpc) neurons and the striatal dopaminergic fibers through the activation of GHS-R1a. We also found that ghrelin reduced nitrotyrosine levels and improved the impairment of rota-rod performance. Ghrelin prevents MPTP-induced microglial activation in the SNpc and striatum, the expression of pro-inflammatory molecules tumor necrosis factor alpha (TNF-alpha) and interleukin-1beta (IL-1beta), and the activation of inducible nitric oxide synthase. The inhibitory effect of ghrelin on the activation of microglia appears to be indirect by suppressing matrix metalloproteinase-3 (MMP-3) expression in stressed dopaminergic neurons because GHS-R1a is not expressed in SNpc microglial cells. Finally, in vitro administration of ghrelin prevented 1-methyl-4-phenylpyridinium-induced dopaminergic cell loss, MMP-3 expression, microglial activation, and the subsequent release of TNF-alpha, IL-1beta, and nitrite in mesencephalic cultures. Our data indicate that ghrelin may act as a survival factor for dopaminergic neurons by functioning as a microglia-deactivating factor and suggest that ghrelin may be a valuable therapeutic agent for neurodegenerative diseases such as PD.

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Section: Measurement Of Mptp Metabolismmentioning

confidence: 99%

Neuroprotective Effect of Ghrelin in the 1-Methyl-4-Phenyl-1,2,3,6-Tetrahydropyridine Mouse Model of Parkinson’s Disease by Blocking Microglial Activation

Moon¹,

Kim

Hwang³

et al. 2009

Neurotox Res

183

142

View full text Add to dashboard Cite

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“…The mouse brain tissue sample preparations were modified from methods reported in the literature [10][11][12][13][17][18][19]. Mouse striatal samples were homogenized in 0.4 M HClO 4 (100 mg tissue/ml).…”

Section: Mouse Brain Tissue Sample Preparationmentioning

confidence: 99%

“…The selection criteria of HPLC columns and mobile phase systems are important for detection of MPP + . Hows et al [19] reported a LC/MS/MS method for the determination of MPP + in brain tissue homogenates using reversed phase chromatography with a Synergie Hydro RP column (150 mm × 2.1 mm, i.d., 4 m) and a mobile phase consisting of formic acid and acetonitrile. In Hows's paper, the ion chromatogram of MPP + in a striatal extract sample contained a matrix peak, which eluted after the MPP + peak at 6.2 min.…”

Section: Optimization Of Chromatographic Conditionsmentioning

confidence: 99%

“…The most sensitive assay for the analysis of MPP + was reported by Hows et al using LC/MS/MS [19]. The multiple reaction monitoring (MRM) scan mode on a triple quadrupole mass spectrometer monitors specific daughter ions from dissociation of parent molecular ions.…”

Section: Introductionmentioning

confidence: 99%

“…This approach combined with the specific LC retention time of analytes provides a sensitive and selective analysis that is unique for individual analytes. In Hows's report [19], the separation of MPP + was based on reversed phase chromatography. However, serious peak tailing of MPP + (or possible formation of an isomeric form of MPP + ) in the brain extracts with 0.4 M perchloric acid (HClO 4 ) was observed while reproducing this method in our lab, resulting in low sensitivity for detection of MPP + .…”

Section: Introductionmentioning

confidence: 99%

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