Acute effects of 1-methyl-4-phenylpyridinium ion (MPP+) on dopamine and serotonin metabolism in rat striatum as assayed in vivo by a micro-dialysis technique

• DOI: 10.1007/bf01253601
• Publication Date: 2005-03-23T11:49:11Z
• Authors: N. Ozaki; D. Nakahara; N. Kaneda; K. Kiuchi; T. Okada; Y. Kasahara; T. Nagatsu
• Keywords: Male; 1-Methyl-4-phenylpyridinium; Serotonin; 0303 health sciences; Dopamine; Neurotoxins; Pyridinium Compounds; Rats, Inbred Strains; Corpus Striatum; Rats; 3. Good health; 03 medical and health sciences; Animals; Monoamine Oxidase; Chromatography, High Pressure Liquid

The acute effect of 1-methyl-4-phenylpyridinium ion (MPP+), a neurotoxin derived from 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), was examined by the in vivo micro-dialysis technique. A dialysis cannula was implanted into rat striatum, and the changes in the concentrations of dopamine (DA), 3, 4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5-HIAA) in the perfusate every 20 min after administration of MPP+ were determined by high-performance liquid chromatography with electrochemical detection (HPLC-ED). After MPP+ administration the levels of DOPAC, HVA and 5-HIAA were markedly decreased. On the contrary the level of DA was markedly increased and reached a maximum 40 min after beginning of the MPP+ administration. By postmortem analysis of the striatal tissue MPP+ was proved to cause the inhibition of monoamine oxidase (MAO), especially MAO-B. These results suggest that the acute biochemical changes induced by MPP+ in vivo were MAO inhibition and release of DA.