Melatonin fails to protect against long-term MPTP-induced dopamine depletion in mouse striatum.

Neurotox Res

Harvey W. Peters Center, Department of Chemistry, VA-MD Regional College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061-0212, USA.

Published: April 2000

Several laboratories recently have reported that melatonin may possess neuroprotective properties. The present paper presents the results of our studies on the long term in vivo neuroprotective effects of melatonin in a well-defined neurotoxicity model using 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in the C57BL/6 mouse. MPTP is bioactivated by brain monoamine oxidase B (MAO-B) to its neurotoxic pyridinium metabolite 1-methyl-4-phenylpyridinium (MPP(+)) which destroys dopaminergic nerve terminals leading to the depletion of neostriatal dopamine (DA) and 3,4-dihydroxyphenylacetic acid (DOPAC). Our initial study compared striatal DA and DOPAC levels in MPTP-only-treated animals and animals treated with melatonin 30 min prior to and 3 times hourly post-MPTP. DA/DOPAC levels measured 7 days after MPTP were similar in both groups. A second study was designed to address the possibility that melatonin cleared from the brain prior to MPP(+). Animals, that had been administered the same regimen of melatonin as in the first study plus a fourth post-MPTP melatonin dose, were maintained on melatonin in drinking water until 5 days post-MPTP. Striatal DA/DOPAC levels of these melatonin-plus-MPTP treated animals also were the same as the MPTP-only-treated animals. In vitro studies confirmed that melatonin is not an inhibitor of MAO-B. These data demonstrate that melatonin does not have any significant protective effects against the long-term striatal DA and DOPAC depletion induced by MPTP in the C57BL/6 mouse.

Download full-text PDF

Source
http://dx.doi.org/10.1007/BF03033256DOI Listing

Publication Analysis

Top Keywords

melatonin
10
mptp c57bl/6
8
c57bl/6 mouse
8
striatal dopac
8
mptp-only-treated animals
8
da/dopac levels
8
animals
5
melatonin fails
4
fails protect
4
protect long-term
4

Similar Publications

Melatonin increases Pb tolerance in P. ovata seedlings via the regulation of growth and stress-related phytohormones, ROS scavenging and genes responsible for melatonin synthesis, metal chelation, and stress defense. Lead (Pb) is a highly toxic heavy metal that accumulates in plants through soil and air contamination and impairs its plant growth and development.

View Article and Find Full Text PDF

Background: Insulinoma is a neuroendocrine tumor, the main manifestation of which is hypoglycemia. However, the symptoms of hypoglycemia can be non-specific for a long time, especially outside provocative conditions, and quite often the tumor manifests from a life-threatening condition - hypoglycemic coma. In this regard, timely laboratory diagnosis of insulinoma and determination of its aggressive course is one of the priorities in modern researches.

View Article and Find Full Text PDF

Melatonin regulation and the function of the periodontal ligament: Future perspective and challenges.

World J Stem Cells

January 2025

Section of Dentistry, Department of Clinical, Surgical, Diagnostic and Paediatric Sciences, University of Pavia, Pavia 27100, Italy.

The present article reviews the emerging role of melatonin (MT) and the Hippo-Yes-associated protein signaling pathway in periodontal regeneration, highlighting their potential to delay the aging process of periodontal ligament stem cells (PDLSCs). Oxidative stress and cellular senescence are major obstacles in regenerative therapies, especially in an aging population. MT, a potent antioxidant, restores the morphology, proliferation, and osteogenic differentiation potential of PDLSCs under oxidative stress conditions.

View Article and Find Full Text PDF

Background: This study investigates the protective properties of melatonin in an Parkinson's disease (PD) model, focusing on the underlying mechanisms involving heat shock proteins (HSPs).

Methods: Twelve adult male C57BL/6 mice were randomly divided into four groups (normal control, melatonin control, Parkinson's model, and melatonin treatment; = 3 per group) and housed in a single cage. 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) was injected intraperitoneally in the Parkinson's model and treatment groups to establish a subacute PD model, while controls received saline.

View Article and Find Full Text PDF

Introduction: Melatonin significantly enhances the tolerance of plants to biotic and abiotic stress, and plays an important role in plant resistance to salt stress. However, its role and molecular mechanisms in eggplant salt stress resistance have been rarely reported. In previous studies, we experimentally demonstrated that melatonin can enhance the salt stress resistance of eggplants.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!