Ottocento

Felten, Hans; Hausmann, Frank-Rutger; Janowski, Franca; Kapp, Volker; Stillers, Rainer; Thoma, Heinz; Wetzel, Hermann H.

doi:10.1007/978-3-476-03417-5_7

Cited by 2 publications

(1 citation statement)

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“…This suggests that hydrogen peroxide produced within glial cells by MAO-B in the SN is either broken down to H,O within these cells by the glutathione system or diffuses into vulnerable nearby DA neurons. Age-related increases in MAO-B have been shown to correlate with DA cell losses in this area of the brain (Cohen, 1986;Felten et al, 1992;Olanow, 1992). In addition, in-creases in levels of free iron, lipid peroxidation, and DNA damage have all been documented in the substantia nigra of PD patients compared with age-matched controls (Dexter et al, 1989a;Dexter et al, 1989b;Sanchez-Ramos et al, 1994).…”

Section: Discussionmentioning

confidence: 99%

Genetic elevation of monoamine oxidase levels in dopaminergic PC12 cells results in increased free radical damage and sensitivity to MPTP

Wei¹,

Yeung²,

Jurma³

et al. 1996

J. Neurosci. Res.

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Production of hydrogen peroxide as a by-product of the breakdown of catecholamines by the enzyme monoamine oxidase (MAO) has been hypothesized to contribute to the increased proclivity of dopaminergic neurons for oxidative injury. We established clonal dopaminergic PC12 cell lines which have elevated MAO activity levels resulting from transgenic expression of the B isoform of the enzyme. Both MAO-A and MAO-B have relatively equivalent affinities for dopamine, and since PC12 primarily express the A and not the B form of the enzyme, this allowed us to distinguish the transgenic MAO activity in these cells from endogenous using the MAO-B specific substrate PEA. Elevation of MAO activity levels in the MAO-B+ cells resulted in higher levels of both free radicals and free radical damage compared with controls. In addition, increased MAO-B levels within PC12 cells caused a dose-dependent increase in sensitivity to the toxin MPTP. Our data suggests that oxidation of catecholamines by MAO can contribute to free radical damage in catecholaminergic neurons and that the low MAO-B activity levels found endogenously in these cells likely accounts for their relative resistance to MPTP toxicity.

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Section: Discussionmentioning

confidence: 99%