title: Increased melatonin may play dual roles in the striata of a 6-hydroxydopamine model of Parkinson's disease.
abstract: OBJECTIVE
  To investigate dynamic changes and roles of melatonin (MLT) in the striata of 6-hydroxydopamine (6-OHDA)-treated rats.
  
  
  METHODS
  A Parkinson's disease (PD) rat was established by a unilateral injection of 6-OHDA into the right substantia nigra pars compacta (SNc) and the right medial forebrain bundle (MFB) to achieve a complete lesion of the ipsilateral nigrostriatal DA system. Dialysates were collected in the lesioned striatum at different time intervals by in vivo microdialysis. In addition, both contralateral and ipsilateral striatum tissues were collected at two time intervals (10:00 and 22:00 h) at 3 and 6 weeks after lesioning. The levels of DA, 3, 4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in the dialysates, as well as MLT in the dialysates and tissues were determined using HPLC.
  
  
  RESULTS
  The dialysate contents of DA, DOPAC and HVA in the lesioned striatum were significantly decreased (P<0.001) in comparison with those in the controls or in the unlesioned side 3 weeks after lesioning while the extracellular level of MLT in the lesioned striatum in these corresponding time intervals distinctly increased when compared with those in the controls (P<0.05). The tissue MLT contents increased in the bilateral striata in different degrees at 6 weeks post-lesion (P<0.05). Moreover, increased MLT levels correlate well with rotations or DA changes in the lesioned striatum.
  
  
  CONCLUSIONS
  These data suggest that 6-OHDA lesion manipulates the MLT secretion pattern. Increased striatal MLT level by a unilateral intracerebral injection of 6-OHDA may play dual roles in the progression of PD in rats.
authors: Research Center of Neurobiology, Fujian Medical University, Fuzhou 350004, China.
authors: Ling
authors: L
authors: Lin
authors: Tao
authors: T
authors: Meng
authors: Tingting
authors: T
authors: Liu
authors: Zhihong
authors: Z
authors: Zheng
mesh_terms: D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D003342:Corpus Striatum / Q000378:metabolism*; D003627:Data Interpretation, Statistical; D004195:Disease Models, Animal; D004298:Dopamine / Q000378:metabolism; D006719:Homovanillic Acid / Q000378:metabolism; D008297:Male; D008550:Melatonin / Q000378:metabolism*; D017551:Microdialysis; D016627:Oxidopamine / Q000493:pharmacokinetics / Q000494:pharmacology; D010302:Parkinson Disease, Secondary / Q000139:chemically induced / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D015102:3,4-Dihydroxyphenylacetic Acid; D016627:Oxidopamine; D008550:Melatonin; D004298:Dopamine; D006719:Homovanillic Acid