Effects of adenosine receptor antagonists on the in vivo LPS-induced inflammation model of Parkinson's disease

Neurotox Res. 2013 Jul;24(1):29-40. doi: 10.1007/s12640-012-9372-1. Epub 2013 Jan 8.

Abstract

The study shows effects of the nonselective adenosine A1/A2A receptor antagonist caffeine and the selective A2A receptor antagonist KW6002 on LPS-induced changes in the extracellular levels of dopamine (DA), glutamate, adenosine, hydroxyl radical, and A2A receptor density in the rat striatum. Intrastriatal LPS (10 μg) injection decreased extracellular level of DA and increased the level of adenosine, glutamate, and hydroxyl radical on the ipsilateral side 24 h after LPS administration. Caffeine (10 and 20 mg/kg i.p.) and KW6002 (1.5 and 3 mg/kg i.p.) given once daily for 6 days and on the 7th day 2 h before and 4 h after LPS injection reversed the LPS-induced changes in extracellular levels of DA, adenosine, glutamate, and hydroxyl radical production. Moreover, LPS-induced decrease in the striatal A2A receptor density was increased by caffeine and KW6002. In order to show the late LPS effect on oxidative damage of DA neurons, the contents of DA, DOPAC, HVA, and hydroxyl radical were determined 72 h after LPS (10 μg) administration into both striata. LPS decreased striatal and substantia nigra content of DA, DOPAC, and HVA while increased striatal but not nigral content of hydroxyl radical. Caffeine (20 mg/kg) and KW60002 (3 mg/kg) given once daily for 6 days and on the 7th day 2 h before and 4 h after intrastriatal injection of LPS normalized the content of DA and its metabolites in both brain regions as well as decreased LPS-induced increase in the striatal level of hydroxyl radical. In conclusion, our data demonstrated antioxidant effects of caffeine and KW6002 in the inflammatory model of PD.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine / metabolism
  • Adenosine A2 Receptor Antagonists / pharmacology*
  • Adenosine A2 Receptor Antagonists / therapeutic use
  • Animals
  • Caffeine / pharmacology*
  • Caffeine / therapeutic use
  • Corpus Striatum / drug effects*
  • Corpus Striatum / metabolism*
  • Dopamine / metabolism
  • Dopaminergic Neurons / drug effects
  • Dopaminergic Neurons / metabolism
  • Glutamic Acid / metabolism
  • Hydroxyl Radical / metabolism
  • Inflammation / chemically induced
  • Lipopolysaccharides / pharmacology*
  • Male
  • Microinjections
  • Parkinson Disease / drug therapy*
  • Parkinson Disease / pathology*
  • Purines / pharmacology*
  • Purines / therapeutic use
  • Rats
  • Receptor, Adenosine A2A / metabolism

Substances

  • Adenosine A2 Receptor Antagonists
  • Lipopolysaccharides
  • Purines
  • Receptor, Adenosine A2A
  • istradefylline
  • Hydroxyl Radical
  • Caffeine
  • Glutamic Acid
  • Adenosine
  • Dopamine