Manganese neurotoxic time course is not influenced by L-deprenyl systemic treatment: influence of L-deprenyl in manganese neurotoxic time course.
Unilateral microinjection of manganese into the rat substantia nigra pars compacta (SNpc) leads to the death of nigral neurons and a decrease in dopamine (DA) within the ipsilateral striatum. L-deprenyl, an irreversible inhibitor of monoamine oxidase B, appears to protect or rescue dopaminergic nigral neurons from the toxic effects of 6-hydroxydopamine (6-OHDA) and 1-methyl-4 phenyl-1, 2, 3, 6-tetrahydropiridine (MPTP). In this study we aimed to investigate whether L-deprenyl is able to influence the manganese neurotoxic time course. L-deprenyl rescue activity was evaluated in discontinuous posology and its protective effect was evaluated in a continuous one. Apomorphine-induced rotational behavior and striatal tyrosine hydroxylase immunostaining (TH-IS) were evaluated in both conditions at 24 h, 72 h and 168 h after intranigral microinjections. Our results indicate a failure in L-deprenyl to influence the establishment and time course of rotational response to apomorphine. Strikingly, a further decrease in the tyrosine hydroxylase immunostaining, at 168 h post microinjection in L-deprenyl-treated rats was obtained. Our data revealed no correlation between an increasing rotational behavior and reduction in TH-IS.
Fernandes
Artur
A
Departamento de Ciências Fisiológicas, CCB, Universidade Estadual de Londrina, Caixa Postal 6001, CEP: 86051-970, Londrina, PR, Brazil.
de Oliveira
Eduardo Fontana
EF
de Rezende
Isabel Cristina Vicente
IC
Ponzoni
Silvia
S
D000818:Animals; D001058:Apomorphine / Q000494:pharmacology; D003342:Corpus Striatum / Q000187:drug effects* / Q000378:metabolism; D018491:Dopamine Agonists / Q000494:pharmacology; D007150:Immunohistochemistry; D008297:Male; D008345:Manganese / Q000633:toxicity*; D008996:Monoamine Oxidase Inhibitors / Q000494:pharmacology; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D018696:Neuroprotective Agents / Q000494:pharmacology*; D010784:Photomicrography; D051381:Rats; D012399:Rotation; D012642:Selegiline / Q000494:pharmacology*; D013378:Substantia Nigra / Q000187:drug effects* / Q000378:metabolism; D013997:Time Factors; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism
D018491:Dopamine Agonists; D008996:Monoamine Oxidase Inhibitors; D018696:Neuroprotective Agents; D012642:Selegiline; D008345:Manganese; D014446:Tyrosine 3-Monooxygenase; D001058:Apomorphine