Effects of the neurotoxin MPTP and pargyline protection on extracellular energy metabolites and dopamine levels in the striatum of freely moving rats.
The neurotoxin MPTP is known to induce dopamine release and depletion of ATP in the striatum of rats. Therefore, we studied the changes induced by MPTP and pargyline protection both on striatal dopamine release and on extracellular energy metabolites in freely moving rats, using dual asymmetric-flow microdialysis. A dual microdialysis probe was inserted in the right striatum of rats. MPTP (25mg/kg, 15mg/kg, 10mg/kg) was intraperitoneally administered for three consecutive days. MAO-B inhibitor pargyline (15mg/kg) was systemically administered before neurotoxin administration. The first MPTP dose induced an increase in dialysate dopamine and a decrease of DOPAC levels in striatal dialysate. After the first neurotoxin administration, increases in striatal glucose, lactate, pyruvate, lactate/pyruvate (L/P) and lactate/glucose (L/G) ratios were observed. Subsequent MPTP administrations showed a progressive reduction of dopamine, glucose and pyruvate levels with a concomitant further increase in lactate levels and L/P and L/G ratios. At day 1, pargyline pre-treatment attenuated the MPTP-induced changes in all studied analytes. Starting from day 2, pargyline prevented the depletion of dopamine, glucose and pyruvate while reduced the increase of lactate, L/P ratio and L/G ratio. These in vivo results suggest a pargyline neuroprotection role against the MPTP-induced energetic impairment consequent to mitochondrial damage. This neuroprotective effect was confirmed by TH immunostaining of the substantia nigra.
Department of Clinical and Experimental Medicine, University of Sassari, Viale San Pietro 43/b - 07100, Sassari, Italy.
Gianfranco
G
Bazzu
Gaia
G
Rocchitta
Rossana
R
Migheli
Maria Domenica
MD
Alvau
Manuel
M
Zinellu
Giulia
G
Puggioni
Giammario
G
Calia
Giulia
G
Mercanti
Pietro
P
Giusti
Maria Speranza
MS
Desole
Pier Andrea
PA
Serra
D000818:Animals; D003342:Corpus Striatum / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism*; D004734:Energy Metabolism / Q000187:drug effects*; D020267:MPTP Poisoning / Q000378:metabolism*; D008297:Male; D008996:Monoamine Oxidase Inhibitors / Q000627:therapeutic use*; D010293:Pargyline / Q000627:therapeutic use*; D051381:Rats; D017208:Rats, Wistar
D008996:Monoamine Oxidase Inhibitors; D010293:Pargyline; D004298:Dopamine
Dopamine; Energy metabolism; Glucose; In vivo microdialysis; Lactate; MPTP; Pargyline; Pyruvate